Two recent tests of loop quantum gravity theory

<!DOCTYPE html> <html id="XF" lang="en-US" dir="LTR" data-app="public" data-template="thread_view" data-container-key="node-66" data-content-key="thread-1061460" data-logged-in="false" data-cookie-prefix="xf_" data-csrf="1740275182,f09366488176b7f82cfbccf1d7ecada0" class="has-no-js template-thread_view XenBase layout-default style-light sidebar-right xb-toggle-default xb-sidebar-show" > <head>  <script async src="https://www.googletagmanager.com/gtag/js?id=UA-2209856-4"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'UA-2209856-4'); </script> <meta charset="utf-8" /> <meta http-equiv="X-UA-Compatible" content="IE=Edge" /> <meta name="viewport" content="width=device-width, initial-scale=1, viewport-fit=cover"> <title>Two recent tests of loop quantum gravity theory</title> <link rel="manifest" href="/webmanifest.php"> <meta name="theme-color" content="#466288" /> <meta name="apple-mobile-web-app-title" content="Physics Forums"> <link rel="apple-touch-icon" href="https://www.physicsforums.com/misc/PhysicsForums_logo_192.png"> <meta name="description" content="2 recent gains on loop quantum gravity theory arXiv:2403.18606 (gr-qc) [Submitted on 27 Mar 2024] Test the Loop Quantum Gravity Theory via the Lensing..." /> <meta property="og:description" content="2 recent gains on loop quantum gravity theory arXiv:2403.18606 (gr-qc) [Submitted on 27 Mar 2024] Test the Loop Quantum Gravity Theory via the Lensing Effect Lai Zhao, Meirong Tang, Zhaoyi Xu Recently, scholars such as Lewandowski, Ma, and Yang have successfully derived a quantum-corrected..." /> <meta property="twitter:description" content="2 recent gains on loop quantum gravity theory arXiv:2403.18606 (gr-qc) [Submitted on 27 Mar 2024] Test the Loop Quantum Gravity Theory via the Lensing Effect Lai Zhao, Meirong Tang, Zhaoyi Xu..." /> <meta property="og:url" content="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <link rel="canonical" href="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <script>document.documentElement.className+=' has-no-fa-brands';</script> <meta property="og:site_name" content="Physics Forums: Science Discussion, Homework Help, Articles" /> <meta property="og:type" content="website" /> <meta property="og:title" content="Two recent tests of loop quantum gravity theory" /> <meta property="twitter:title" content="Two recent tests of loop quantum gravity theory" /> <meta property="og:image" content="https://www.physicsforums.com/styles/physicsforums/images/physics-forums-logo-og.png" /> <meta property="twitter:image" content="https://www.physicsforums.com/styles/physicsforums/images/physics-forums-logo-og.png" /> <meta property="twitter:card" content="summary" /> <link rel="stylesheet" href="/css.php?css=public%3Anormalize.css%2Cpublic%3Afa.css%2Cpublic%3Acore.less%2Cpublic%3Aapp.less&s=12&l=1&d=1740257292&k=9d0860d3ac6d1d035719345d5207661b971a33e3" /> <link rel="stylesheet" href="/css.php?css=public%3Abb_code.less%2Cpublic%3Amessage.less%2Cpublic%3Apf_first_post_rss.css%2Cpublic%3Aphysicsforums_badges.less%2Cpublic%3Ashare_controls.less%2Cpublic%3Astructured_list.less%2Cpublic%3Athxpress_xf.less%2Cpublic%3Axb.less%2Cpublic%3Aextra.less&s=12&l=1&d=1740257292&k=9c14e37ec294ab0a1d153006a30b72cc0bbc6c76" /> <script src="/js/xf/preamble.min.js?_v=bab3e795"></script> <link rel="icon" type="image/png" href="https://www.physicsforums.com/favicon.ico" sizes="32x32" /> <meta name="theme-color" content="#0275b4"> </head> <body data-template="thread_view" class=" "> <div class="p-pageWrapper" id="top"> <div class="p-pageWrapper--helper"></div> <div class="xb-page-wrapper xb-canvas-menuActive"> <div class="xb-page-wrapper--helper"></div> <div class="xb-content-wrapper"> <div class="navigation-helper"></div> <div class="p-navSticky p-navSticky--primary" data-xf-init="sticky-header"> <div class="p-nav--wrapper"> <nav class="p-nav"> <div class="p-nav-inner"> <button type="button" class="button--plain p-nav-menuTrigger button" data-xf-click="off-canvas" data-menu=".js-headerOffCanvasMenu" tabindex="0" aria-label="Menu"><span class="button-text"> <i aria-hidden="true"></i> </span></button> <div class="p-nav-smallLogo"> <a href="/"> <img src="https://www.physicsforums.com/styles/physicsforums/xenforo/logo.png" srcset="" alt="Physics Forums: Science Discussion, Homework Help, Articles" width="274" height="51" /> <img src="https://www.physicsforums.com/styles/physicsforums/xenforo/logosmall.png" width="52" height="50" alt="Physics Forums: Science Discussion, Homework Help, Articles" class="logo-mobile" /> </a> </div> <div class="p-nav-scroller hScroller" data-xf-init="h-scroller" data-auto-scroll=".p-navEl.is-selected"> <div class="hScroller-scroll"> <ul class="p-nav-list js-offCanvasNavSource"> <li class="navthxlink_1"> <div class="p-navEl " data-has-children="true"> <a href="https://www.physicsforums.com/insights/" class="p-navEl-link p-navEl-link--splitMenu " data-nav-id="thxlink_1">Insights Blog</a> <a data-xf-key="1" data-xf-click="menu" data-menu-pos-ref="< .p-navEl" class="p-navEl-splitTrigger" role="button" tabindex="0" aria-label="Toggle expanded" aria-expanded="false" aria-haspopup="true"></a> <div class="menu menu--structural" data-menu="menu" aria-hidden="true"> <div class="menu-content"> <a href="https://www.physicsforums.com/insights/postindex/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="toc">-- Browse All Articles --</a> <a href="https://www.physicsforums.com/insights/science-math-articles/physics-articles/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="physarticles">Physics Articles</a> <a href="https://www.physicsforums.com/insights/science-math-tutorials/physics-tutorials/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="phystuts">Physics Tutorials</a> <a href="https://www.physicsforums.com/insights/science-math-guides/physics-guides/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="physguides">Physics Guides</a> <a href="https://www.physicsforums.com/insights/science-math-faqs/physics-faqs/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="physfaq">Physics FAQ</a> <a href="https://www.physicsforums.com/insights/science-math-articles/math-articles/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="mathart">Math Articles</a> <a href="https://www.physicsforums.com/insights/science-math-tutorials/math-tutorials/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="mathtuts">Math Tutorials</a> <a href="https://www.physicsforums.com/insights/science-math-guides/math-guides/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="mathguide">Math Guides</a> <a href="https://www.physicsforums.com/insights/science-math-faqs/math-faqs/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="mathfaq">Math FAQ</a> <a href="https://www.physicsforums.com/insights/science-math-articles/education-articles/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="eduart">Education Articles</a> <a href="https://www.physicsforums.com/insights/science-math-guides/education-guides/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="eduguide">Education Guides</a> <a href="https://www.physicsforums.com/insights/science-math-articles/biology-chemistry-articles/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="biochemart">Bio/Chem Articles</a> <a href="https://www.physicsforums.com/insights/science-math-guides/technology-guides/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="techguides">Technology Guides</a> <a href="https://www.physicsforums.com/insights/science-math-tutorials/computer-science-tutorials/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="compscitut">Computer Science Tutorials</a> </div> </div> </div> </li> <li class="navforums"> <div class="p-navEl is-selected" data-has-children="true"> <a href="https://www.physicsforums.com/" class="p-navEl-link p-navEl-link--splitMenu " data-nav-id="forums">Forums</a> <a data-xf-key="2" data-xf-click="menu" data-menu-pos-ref="< .p-navEl" class="p-navEl-splitTrigger" role="button" tabindex="0" aria-label="Toggle expanded" aria-expanded="false" aria-haspopup="true"></a> <div class="menu menu--structural" data-menu="menu" aria-hidden="true"> <div class="menu-content"> <a href="https://www.physicsforums.com/forums/classical-physics.61/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="quantum">Classical Physics</a> <a href="https://www.physicsforums.com/forums/quantum-physics.62/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="quantummech">Quantum Physics</a> <a href="https://www.physicsforums.com/forums/quantum-interpretations-and-foundations.292/" class="menu-linkRow u-indentDepth1 js-offCanvasCopy " data-nav-id="quantum_inter">Quantum Interpretations</a> <hr class="menu-separator" /> <a href="https://www.physicsforums.com/forums/special-and-general-relativity.70/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="genrel">Special and General Relativity</a> <a href="https://www.physicsforums.com/forums/atomic-and-condensed-matter.64/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="atomicphys">Atomic and Condensed Matter</a> <a href="https://www.physicsforums.com/forums/high-energy-nuclear-particle-physics.65/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="highenergy">Nuclear and Particle Physics</a> <a href="https://www.physicsforums.com/forums/beyond-the-standard-model.66/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="standardmodel">Beyond the Standard Model</a> <a href="https://www.physicsforums.com/forums/cosmology.69/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="cosmo">Cosmology</a> <a href="https://www.physicsforums.com/forums/astronomy-and-astrophysics.71/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="astrophysics">Astronomy and Astrophysics</a> <a href="https://www.physicsforums.com/forums/other-physics-topics.111/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="otherphys">Other Physics Topics</a> </div> </div> </div> </li> <li class="navhotthreads1"> <div class="p-navEl " > <a href="https://www.physicsforums.com/whats-new/hot-threads" class="p-navEl-link " data-xf-key="3" data-nav-id="hotthreads1">Trending</a> </div> </li> <li class="navfeaturedthreads1"> <div class="p-navEl " > <a href="https://www.physicsforums.com/threads/featured" class="p-navEl-link " data-xf-key="4" data-nav-id="featuredthreads1">Featured Threads</a> </div> </li> </ul> </div> </div> <div class="p-nav-opposite"> <div class="p-navgroup p-account p-navgroup--guest"> <a href="/login/" class="p-navgroup-link p-navgroup-link--textual p-navgroup-link--logIn" data-xf-click="overlay" data-follow-redirects="on"> <span class="p-navgroup-linkText">Log in</span> </a> <a href="/login/register" class="p-navgroup-link p-navgroup-link--textual p-navgroup-link--register" data-xf-click="overlay" data-follow-redirects="on"> <span class="p-navgroup-linkText">Register</span> </a> </div> <div class="p-navgroup p-discovery"> <a href="/whats-new/" class="p-navgroup-link p-navgroup-link--iconic p-navgroup-link--whatsnew" aria-label="What's new" title="What's new"> <i aria-hidden="true"></i> <span class="p-navgroup-linkText">What's new</span> </a> <a href="/search/" class="p-navgroup-link p-navgroup-link--iconic p-navgroup-link--search" data-xf-click="menu" data-xf-key="/" aria-label="Search" aria-expanded="false" aria-haspopup="true" title="Search"> <i aria-hidden="true"></i> <span class="p-navgroup-linkText">Search</span> </a> <div class="menu menu--structural menu--wide" data-menu="menu" aria-hidden="true"> <form action="/search/search" method="post" class="menu-content" data-xf-init="quick-search"> <h3 class="menu-header">Search</h3> <div class="menu-row"> <a href="https://www.google.com/search?q=physics+forums" rel='nofollow,noreferrer'><b>Google search</b></a>: add "Physics Forums" to query<br><br> <div class="inputGroup inputGroup--joined"> <input type="text" class="input" name="keywords" placeholder="Search…" aria-label="Search" data-menu-autofocus="true" /> <select name="constraints" class="js-quickSearch-constraint input" aria-label="Search within"> <option value="">Everywhere</option> <option value="{"search_type":"post"}">Threads</option> <option value="{"search_type":"post","c":{"nodes":[66],"child_nodes":1}}">This forum</option> <option value="{"search_type":"post","c":{"thread":1061460}}">This thread</option> </select> </div> </div> <div class="menu-row"> <label class="iconic"><input type="checkbox" name="c[title_only]" value="1" /><i aria-hidden="true"></i><span class="iconic-label">Search titles only <span tabindex="0" role="button" data-xf-init="tooltip" data-trigger="hover focus click" title="Tags will also be searched in content where tags are supported"> <i class="fa--xf far fa-question-circle u-muted u-smaller" aria-hidden="true"></i> </span></span></label> </div> <div class="menu-row"> <div class="inputGroup"> <span class="inputGroup-text" id="ctrl_search_menu_by_member">By:</span> <input type="text" class="input" name="c[users]" data-xf-init="auto-complete" placeholder="Member" aria-labelledby="ctrl_search_menu_by_member" /> </div> </div> <div class="menu-footer"> <span class="menu-footer-controls"> <button type="submit" class="button--primary button button--icon button--icon--search"><span class="button-text">Search</span></button> <a href="/search/" class="button"><span class="button-text">Advanced search…</span></a> </span> </div> <input type="hidden" name="_xfToken" value="1740275182,f09366488176b7f82cfbccf1d7ecada0" /> </form> </div> </div> </div> </div> </nav> </div> </div> <div class="p-sectionLinks--wrapper"> <div class="p-sectionLinks"> <div class="p-sectionLinks-inner"> <div class="hScroller" data-xf-init="h-scroller"> <div class="hScroller-scroll"> <ul class="p-sectionLinks-list"> <li> <div class="p-navEl " > <a href="https://www.physicsforums.com/forums/classical-physics.61/" class="p-navEl-link " data-xf-key="alt+1" data-nav-id="quantum">Classical Physics</a> </div> </li> <li> <div class="p-navEl " data-has-children="true"> <a href="https://www.physicsforums.com/forums/quantum-physics.62/" class="p-navEl-link p-navEl-link--splitMenu " data-nav-id="quantummech">Quantum Physics</a> <a data-xf-key="alt+2" data-xf-click="menu" data-menu-pos-ref="< .p-navEl" class="p-navEl-splitTrigger" role="button" tabindex="0" aria-label="Toggle expanded" aria-expanded="false" aria-haspopup="true"></a> <div class="menu menu--structural" data-menu="menu" aria-hidden="true"> <div class="menu-content"> <a href="https://www.physicsforums.com/forums/quantum-interpretations-and-foundations.292/" class="menu-linkRow u-indentDepth0 js-offCanvasCopy " data-nav-id="quantum_inter">Quantum Interpretations</a> </div> </div> </div> </li> <li> <div class="p-navEl " > <a href="https://www.physicsforums.com/forums/special-and-general-relativity.70/" class="p-navEl-link " data-xf-key="alt+3" data-nav-id="genrel">Special and General Relativity</a> </div> </li> <li> <div class="p-navEl " > <a href="https://www.physicsforums.com/forums/atomic-and-condensed-matter.64/" class="p-navEl-link " data-xf-key="alt+4" data-nav-id="atomicphys">Atomic and Condensed Matter</a> </div> </li> <li> <div class="p-navEl " > <a href="https://www.physicsforums.com/forums/high-energy-nuclear-particle-physics.65/" class="p-navEl-link " data-xf-key="alt+5" data-nav-id="highenergy">Nuclear and Particle Physics</a> </div> </li> <li> <div class="p-navEl " > <a href="https://www.physicsforums.com/forums/beyond-the-standard-model.66/" class="p-navEl-link " data-xf-key="alt+6" data-nav-id="standardmodel">Beyond the Standard Model</a> </div> </li> <li> <div class="p-navEl " > <a href="https://www.physicsforums.com/forums/cosmology.69/" class="p-navEl-link " data-xf-key="alt+7" data-nav-id="cosmo">Cosmology</a> </div> </li> <li> <div class="p-navEl " > <a href="https://www.physicsforums.com/forums/astronomy-and-astrophysics.71/" class="p-navEl-link " data-xf-key="alt+8" data-nav-id="astrophysics">Astronomy and Astrophysics</a> </div> </li> <li> <div class="p-navEl " > <a href="https://www.physicsforums.com/forums/other-physics-topics.111/" class="p-navEl-link " data-xf-key="alt+9" data-nav-id="otherphys">Other Physics Topics</a> </div> </li> </ul> </div> </div> <div class="p-sectionLinks-right"> </div> </div> </div> </div> <div class="offCanvasMenu offCanvasMenu--nav js-headerOffCanvasMenu" data-menu="menu" aria-hidden="true" data-ocm-builder="navigation"> <div class="offCanvasMenu-backdrop" data-menu-close="true"></div> <div class="offCanvasMenu-content"> <div class="offCanvasMenu-content--inner"> <div class="offCanvasMenu-header"> Menu <a class="offCanvasMenu-closer" data-menu-close="true" role="button" tabindex="0" aria-label="Close"></a> </div> <div class="p-offCanvasRegisterLink"> <div class="offCanvasMenu-linkHolder"> <a href="/login/" class="offCanvasMenu-link" data-xf-click="overlay" data-menu-close="true"> Log in </a> </div> <hr class="offCanvasMenu-separator" /> <div class="offCanvasMenu-linkHolder"> <a href="/login/register" class="offCanvasMenu-link" data-xf-click="overlay" data-menu-close="true"> Register </a> </div> <hr class="offCanvasMenu-separator" /> </div> <div class="offCanvasMenu-subHeader">Navigation</div> <div class="js-offCanvasNavTarget"></div>  <div class="offCanvasMenu-subHeader">More options</div> <div class="offCanvasMenu-linkHolder"> <a href="/misc/contact" class="offCanvasMenu-link" data-menu-close="true" data-nav-id="contactUs" data-xf-click="overlay">Contact us</a> </div> <div class="offCanvasMenu-linkHolder"> <a class="offCanvasMenu-link" data-menu-close="true" data-nav-id="closeMenu" role="button" tabindex="0" aria-label="Close">Close Menu</a> </div> </div> </div> </div> <div class="p-body"> <div class="p-body-inner">  <noscript class="js-jsWarning"><div class="blockMessage blockMessage--important blockMessage--iconic u-noJsOnly">JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.</div></noscript> <div class="blockMessage blockMessage--important blockMessage--iconic js-browserWarning" style="display: none">You are using an out of date browser. It may not display this or other websites correctly.<br />You should upgrade or use an <a href="https://www.google.com/chrome/" target="_blank" rel="noopener">alternative browser</a>.</div> <div class="p-body-main p-body-main--withSidebar "> <div class="p-body-contentCol"></div> <div class="p-body-sidebarCol"></div> <div class="p-body-content"> <div class="p-body-pageContent"> <div class="p-breadcrumbs--parent "> <ul class="p-breadcrumbs " itemscope itemtype="https://schema.org/BreadcrumbList"> <li itemprop="itemListElement" itemscope itemtype="https://schema.org/ListItem"> <a href="https://www.physicsforums.com/" itemprop="item"> <span itemprop="name">Forums</span> </a> <meta itemprop="position" content="1" /> </li> <li itemprop="itemListElement" itemscope itemtype="https://schema.org/ListItem"> <a href="/#physics.9" itemprop="item"> <span itemprop="name">Physics</span> </a> <meta itemprop="position" content="2" /> </li> <li itemprop="itemListElement" itemscope itemtype="https://schema.org/ListItem"> <a href="/forums/beyond-the-standard-models.66/" itemprop="item"> <span itemprop="name">Beyond the Standard Models</span> </a> <meta itemprop="position" content="3" /> </li> </ul> </div> <div class="p-body-header"> <div class="p-title "> <h1 class="p-title-value">Two recent tests of loop quantum gravity theory </h1> </div> <div class="p-description"> <ul class="listInline listInline--bullet"> <li> <span data-xf-init="tooltip" title="Level: Intermediate (Undergrad)" ><span class="prefix inter" dir="auto">I</span></span> </li> <li> <i class="fa--xf fal fa-user" aria-hidden="true" title="Thread starter"></i> <span class="u-srOnly">Thread starter</span> <span>kodama</span> </li> <li> <i class="fa--xf fal fa-clock" aria-hidden="true" title="Start date"></i> <span class="u-srOnly">Start date</span> <time class="u-dt" dir="auto" datetime="2024-04-02T20:19:55-0500" data-time="1712107195" data-date-string="Apr 2, 2024" data-time-string="8:19 PM" title="Apr 2, 2024 at 8:19 PM">Apr 2, 2024</time> </li> <li> <dl class="tagList tagList--thread-1061460 "> <dt> <i class="fa--xf fal fa-tags" aria-hidden="true" title="Tags"></i> <span class="u-srOnly">Tags</span> </dt> <dd> <span class="js-tagList"> <a href="/tags/gravity/" data-xf-init="preview-tooltip" data-preview-url="/tags/gravity/preview" class="tagItem tagItem--tag_gravity" dir="auto"> Gravity </a> <a href="/tags/loop/" data-xf-init="preview-tooltip" data-preview-url="/tags/loop/preview" class="tagItem tagItem--tag_loop" dir="auto"> Loop </a> <a href="/tags/quantum/" data-xf-init="preview-tooltip" data-preview-url="/tags/quantum/preview" class="tagItem tagItem--tag_quantum" dir="auto"> Quantum </a> </span> </dd> </dl> </li> </ul> </div> </div> <script src="https://www.physicsforums.com/check-for-tex.js" defer></script> <div class="block block--messages" data-xf-init="" data-type="post" data-href="/inline-mod/" data-search-target="*"> <span class="u-anchorTarget" id="posts"></span> <div class="block-outer"></div> <div class="block-outer js-threadStatusField"></div> <div class="block-container lbContainer" data-xf-init="lightbox select-to-quote" data-message-selector=".js-post" data-lb-id="thread-1061460" data-lb-universal="0"> <div class="block-body js-replyNewMessageContainer">  <article class="message message--post js-post js-inlineModContainer " data-author="kodama" data-content="post-7074315" id="js-post-7074315" > <span class="u-anchorTarget" id="post-7074315"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-04-02T20:19:55-0500" data-time="1712107195" data-date-string="Apr 2, 2024" data-time-string="8:19 PM" title="Apr 2, 2024 at 8:19 PM">Apr 2, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7074315/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #1 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" > <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="551353">kodama</span></span>   <span class="threadstarter" data-xf-init="tooltip" title="Thread Starter"><i class="fal fa-user-edit"></i></span>   </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,026</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>139</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7074315" data-lb-caption-desc="kodama · Apr 2, 2024 at 8:19 PM"> <div class="message-fields message-fields--before"> <dl class="pairs pairs--columns pairs--fixedSmall pairs--customField" data-field="summary"> <dt>TL;DR Summary</dt> <dd>on electromagnetic properties of charged leptons and via the Lensing Effect</dd> </dl> </div> <article class="message-body js-selectToQuote"> <div > <div class="bbWrapper">2 recent gains on loop quantum gravity theory<br /> <br /> arXiv:2403.18606 (gr-qc)<br /> [Submitted on 27 Mar 2024]<br /> Test the Loop Quantum Gravity Theory via the Lensing Effect<br /> Lai Zhao, Meirong Tang, Zhaoyi Xu<br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> Recently, scholars such as Lewandowski, Ma, and Yang have successfully derived a quantum-corrected black hole model in loop quantum gravity (Phys.Rev.Lett.130.101501 (2023)), which is a modification of the Schwarzschild black hole. In this paper, we calculate the strong/weak gravitational lensing effects under the quantum-corrected black hole model, taking the supermassive black holes M87* and SgrA* as the subjects of study to explore the impact of the quantum correction parameter α on the positions of images and the Einstein ring. Our calculations show that in the case of strong gravitational lensing, the lensing coefficient a¯ increases with an increase in the quantum correction parameter, while the deflection angle and the lensing coefficient b¯ decrease with an increase in the quantum correction parameter. The quantum correction parameter α has a significant impact in the context of supermassive black holes. In weak gravitational lensing, the quantum correction parameter α plays a suppressive role. Our theoretical analysis suggests that with advancements in future astrophysical observation techniques, it might be possible to test loop quantum gravity theory using the gravitational lensing effect.<br /> <br /> Subjects: General Relativity and Quantum Cosmology (gr-qc)<br /> Cite as: arXiv:2403.18606 [gr-qc]<br /> (or arXiv:2403.18606v1 [gr-qc] for this version) </div> </div> </blockquote><br /> <a href="https://doi.org/10.48550/arXiv.2403.18606" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://doi.org/10.48550/arXiv.2403.18606</a><br /> <br /> and<br /> <br /> [Submitted on 7 Dec 2023 (v1), last revised 28 Dec 2023 (this version, v2)]<br /> Shadows of Loop Quantum Black Holes: Semi-analytical Simulations of Loop Quantum Gravity Effects on Sagittarius A* and M 87*<br /> Hong-Xuan Jiang, Cheng Liu, Indu K. Dihingia, Yosuke Mizuno, Haiguang Xu, Tao Zhu, Qiang Wu<br /> <br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> In this study, we delve into the observational implications of rotating Loop Quantum Black Holes (LQBHs) within an astrophysical framework. We employ semi-analytical General Relativistic Radiative Transfer (GRRT) computations to study the emission from the accretion flow around LQBHs. Our findings indicate that the increase of Loop Quantum Gravity (LQG) effects results in an enlargement of the rings from LQBHs, thereby causing a more circular polarization pattern in the shadow images. We make comparisons with the Event Horizon Telescope (EHT) observations of Sgr\,A∗ and M\,87∗, which enable us to determine an upper limit for the polymetric function P in LQG. The upper limit for Sgr\,A∗ is 0.2, while for M\,87∗ it is 0.07. Both black holes exhibit a preference for a relatively high spin (a≳0.5 for Sgr\,A∗ and 0.5≲a≲0.7 for M\,87∗). The constraints for Sgr\,A∗ are based on black hole spin and ring diameter, whereas for M\,87∗, the constraints are further tightened by the polarimetric pattern. In essence, our simulations provide observational constraints on the effect of LQG in supermassive black holes (SMBH), providing the most consistent comparison with observation.<br /> Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE)<br /> Cite as: arXiv:2312.04288 [gr-qc]<br /> (or arXiv:2312.04288v2 [gr-qc] for this version) </div> </div> </blockquote><br /> <a href="https://doi.org/10.48550/arXiv.2312.04288" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://doi.org/10.48550/arXiv.2312.04288</a><br /> <br /> and<br /> <br /> arXiv:2305.04336 (gr-qc)<br /> [Submitted on 7 May 2023 (v1), last revised 30 Oct 2023 (this version, v2)]<br /> Strong Gravitational Lensing by Loop Quantum Gravity Motivated Rotating Black Holes and EHT Observations<br /> Jitendra Kumar, Shafqat Ul Islam, Sushant G. Ghosh<br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> We investigate gravitational lensing in the strong deflection regime by loop quantum gravity (LQG)-motivated rotating black hole (LMRBH) metrics with an additional parameter l besides mass M and rotation a. The LMRBH spacetimes are regular everywhere, asymptotically encompassing the Kerr black hole as a particular case and, depending on the parameters, describe black holes with one horizon only (BH-I), black holes with an event horizon and a Cauchy horizon (BH-II), black holes with three horizons (BH-III), or black holes with no horizons (NH) spacetime. It turns out that as the LQG parameter l increases, the unstable photon orbit radius xps, the critical impact parameter ups, the deflection angle αD(θ) and angular position θ∞ also increases. Meanwhile, the angular separation s decreases, and relative magnitude rmag increases with increasing l for prograde motion but they show opposite behaviour for the retrograde motion. For Sgr A*, the angular position θ∞ is ∈ (16.4, 39.8) μas, while for M87* ∈ (12.33, 29.9) μas. The angular separation s, for SMBHs Sgr A* and M87*, differs significantly, with values ranging ∈ (0.008-0.376) μas for Sgr A* and ∈ (0.006-0.282) μas for M87*. We estimate the time delay between the first and second relativistic images using twenty supermassive galactic centre black holes as lenses. Our analysis concludes that, within the 1σ region, a significant portion of the BH-I and BH-II and for a small portion of BH-III parameter space agrees with the EHT results of M87* and Sgr A* whereas NH is completely ruled out. We discover that the EHT results of Sgr A* place more stringent limits on the parameter space of LMRBH black holes than those established by the EHT results of M87*. <br /> <br /> Comments: 16 Pages, 11 Figures, 3 Tables, Accepted for publication in EPJC<br /> Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics of Galaxies (astro-ph.GA)<br /> Cite as: arXiv:2305.04336 [gr-qc]<br /> (or arXiv:2305.04336v2 [gr-qc] for this version) </div> </div> </blockquote><br /> and <br /> <br /> arXiv:2302.10482 (gr-qc)<br /> [Submitted on 21 Feb 2023 (v1), last revised 29 Apr 2023 (this version, v2)]<br /> Observational tests of quantum extension of Schwarzschild spacetime in loop quantum gravity with stars in the galactic center<br /> Jian-Ming Yan, Cheng Liu, Tao Zhu, Qiang Wu, Anzhong Wang<br /> <br /> <br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> In this paper, we use the publicly available observational data of 17 stellar stars orbiting Sgr A* to test the quantum extension of Schwarzschild spacetime in loop quantum gravity (LQG). For our purpose, we transform the geodesical evolution of a massive particle in the quantum-extended Schwarzschild black hole to the perturbed Kepler problem and calculate the effects of LQG on the pericentre advance of the stellar stars. With these effects, one is able to compare them with the publicly available astrometric and spectroscopic data of stellar stars in the galactic center. We perform Monte Carlo Markov Chain (MCMC) simulations to probe the possible LQG effects on the orbit of S-stars. No significant evidence of the quantum-extended Schwarzschild black hole from LQG is found. Among the posterior analyses of 17 S-stars, the result of S2 gives the strongest bound on the LQG parameter Aλ, which places an upper bound at 95\% confidence level on Aλ to be Aλ<0.302. <br /> <br /> Comments: 12 pages, 6 figures<br /> Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)<br /> Cite as: arXiv:2302.10482 [gr-qc]<br /> (or arXiv:2302.10482v2 [gr-qc] for this version)<br /> <br /> <a href="https://doi.org/10.48550/arXiv.2302.10482" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://doi.org/10.48550/arXiv.2302.10482</a><br /> Journal reference: Phys. Rev. D 107, 084043 (2023)<br /> Related DOI: <br /> <a href="https://doi.org/10.1103/PhysRevD.107.084043" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://doi.org/10.1103/PhysRevD.107.084043</a> </div> </div> </blockquote><br /> <br /> arXiv:2403.17197 (hep-th)<br /> [Submitted on 25 Mar 2024]<br /> Loop Quantum Gravity effects on electromagnetic properties of charged leptons<br /> João Paulo S. Melo, Mario J. Neves, Jefferson M. A. Paixão, José A. Helayël-Neto<br /> <br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> The efforts in this contribution consist in reassessing a modified Dirac equation that incorporates a γ0γ5-Lorentz-symmetry violating (LSV) term induced as a Loop Quantum Gravity (LQG) effect. Originally, this equation has been applied and considered as a good scenario for describing a number of investigations on the flight time of cosmic photons and neutrinos, which suggests that the speed of light in vacuum, in connection with the geometry that describes a granular space-time, takes an energy-dependent form, e.g., v(E)=1±E/ELSV, with ELSV≈6,5×1017 GeV for neutrinos. Once LQG provides a viable way to consistently understand this picture, we pursue an analysis of this effective Dirac equation to inspect some of its properties. These include: the derivation of the modified fermionic propagator, attainment of the Gordon decomposition of the vector current with minimal electromagnetic coupling to obtain information on the form factors, examination of the non-relativistic limit of the equation, evaluation of the spin- and velocity-dependent corrections to the Coulomb potential due to LQG effects, and the modified Hamiltonian in the low-relativistic regime. The study of the form factors may open up paths to set up bounds on the LQG parameters from the precision measurements of electromagnetic attributes of the charged leptons, such as their respective electric and magnetic dipole moments.<br /> <br /> Comments: 11 pages, 2 figures<br /> Subjects: High Energy Physics - Theory (hep-th); High Energy Physics - Phenomenology (hep-ph)<br /> Cite as: arXiv:2403.17197 [hep-th]<br /> (or arXiv:2403.17197v1 [hep-th] for this version)) </div> </div> </blockquote><br /> <a href="https://doi.org/10.48550/arXiv.2403.17197" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://doi.org/10.48550/arXiv.2403.17197</a><br /> <br /> any comment on test loop quantum gravity theory on electromagnetic properties of charged leptons and via the Lensing Effect<br /> <br /> are those predictions the strong/weak gravitational lensing effects under the quantum-corrected black hole model, taking the supermassive black holes M87* and SgrA* as the subjects of study on unique to loop quantum gravity theory<br /> or<br /> could string theory, SUGRA, semiclassical gravity also make predictions strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA* via the Lensing Effect<br /> <br /> what if observations of strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA* confirm loop quantum gravity theory<br /> <br /> attributes of the charged leptons, such as their respective electric and magnetic dipole moments is something useful for connecting to experiment by electron EDM<br /> <br /> if loop quantum gravity theory on electromagnetic properties of charged leptons and via the Lensing Effect confirm by future experiment should Nobel Prize be awarded and loop quantum gravity theorywins over string theory ?</div> </div> <div class="js-selectToQuoteEnd"> </div> <div class="googleads_fixed"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-6580726045122001" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-6580726045122001" data-ad-slot="3049969336" data-ad-format="auto" data-full-width-responsive="true"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> </article> </div> <div class="message-lastEdit"> Last edited: <time class="u-dt" dir="auto" datetime="2024-04-03T01:25:20-0500" data-time="1712125520" data-date-string="Apr 3, 2024" data-time-string="1:25 AM" title="Apr 3, 2024 at 1:25 AM">Apr 3, 2024</time> </div> </div> <footer class="message-footer"> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <div class="message-cell message-cell--main" id="post-physorg"> <a href="https://phys.org/physics-news/" target="_blank">Physics news</a> on Phys.org <ul class="phys_items"> <li><a href="https://phys.org/news/2025-02-unexpected-nucleus-prompts-reevaluation-atomic.html" target="_blank">Unexpected shape of lead-208 nucleus prompts reevaluation of atomic nuclei models</a></li> <li><a href="https://phys.org/news/2025-02-scientists-elusive-liquid-transition-deep.html" target="_blank">Scientists map elusive liquid-liquid transition point using deep neural network</a></li> <li><a href="https://phys.org/news/2025-02-links-disparate-pion-reactions-nuclear.html" target="_blank">New calculation links disparate pion reactions in nuclear physics</a></li> </ul> </div> <article class="message message--post js-post js-inlineModContainer " data-author="kodama" data-content="post-7078031" id="js-post-7078031" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7078031/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7078031"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-04-14T14:15:22-0500" data-time="1713122122" data-date-string="Apr 14, 2024" data-time-string="2:15 PM" title="Apr 14, 2024 at 2:15 PM" itemprop="datePublished">Apr 14, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7078031/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #2 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/kodama.551353/"> <meta itemprop="url" content="https://www.physicsforums.com/members/kodama.551353/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="551353"><span itemprop="name">kodama</span></span></span>   <span class="threadstarter" data-xf-init="tooltip" title="Thread Starter"><i class="fal fa-user-edit"></i></span>   </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,026</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>139</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7078031" data-lb-caption-desc="kodama · Apr 14, 2024 at 2:15 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">"Our theoretical analysis suggests that with advancements in future astrophysical observation techniques, it might be possible to test loop quantum gravity theory using the gravitational lensing effect."<br /> <br /> <br /> LQG makes specific predictions on strong gravitational lensing for the supermassive black holes M87* and SgrA* that can be observed, in principle, by Event Horizon Telescope (EHT) observations or future telescopes.<br /> <br /> what if these LQG predictions of gravitational lensing for the supermassive black holes M87* and SgrA* are verified?<br /> <br /> there was a recent solar eclipse in the USA.<br /> <br /> isn't this like the original test of GR vs Newton during the 1919 solar eclipse, here GR vs LQG using gravitational lensing</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="ohwilleke" data-content="post-7078406" id="js-post-7078406" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7078406/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7078406"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-04-15T16:33:14-0500" data-time="1713216794" data-date-string="Apr 15, 2024" data-time-string="4:33 PM" title="Apr 15, 2024 at 4:33 PM" itemprop="datePublished">Apr 15, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7078406/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #3 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/ohwilleke.19562/"> <meta itemprop="url" content="https://www.physicsforums.com/members/ohwilleke.19562/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="19562"><span itemprop="name">ohwilleke</span></span></span>    <div class="post-badges"> <div class="post-badge badge-star" data-xf-init="tooltip" title="Click to Support PF"> <i class="fa--xf fal fa-star" aria-hidden="true"></i><span> Gold Member</span> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>2,578</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>1,530</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7078406" data-lb-caption-desc="ohwilleke · Apr 15, 2024 at 4:33 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">The headline of the OP is a bit misleading. Scientists have proposed ways to test if reality is closer to the LQG or the classical GR prediction. But, nobody has actually done those tests at the level of precision necessary to actually distinguish between the two theories with any meaningful statistical significance.</div> </div> <div class="js-selectToQuoteEnd"> </div> <div class="googleads_fixed"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-6580726045122001" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-6580726045122001" data-ad-slot="5961342082" data-ad-format="auto" data-full-width-responsive="true"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="4" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--1" data-reaction-id="1"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Like" title="Like" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>Crispybacon</bdi>, <bdi>pines-demon</bdi>, <bdi>weirdoguy</bdi> and 1 other person </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="kodama" data-content="post-7078515" id="js-post-7078515" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7078515/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7078515"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-04-16T00:19:55-0500" data-time="1713244795" data-date-string="Apr 16, 2024" data-time-string="12:19 AM" title="Apr 16, 2024 at 12:19 AM" itemprop="datePublished">Apr 16, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7078515/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #4 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/kodama.551353/"> <meta itemprop="url" content="https://www.physicsforums.com/members/kodama.551353/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="551353"><span itemprop="name">kodama</span></span></span>   <span class="threadstarter" data-xf-init="tooltip" title="Thread Starter"><i class="fal fa-user-edit"></i></span>   </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,026</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>139</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7078515" data-lb-caption-desc="kodama · Apr 16, 2024 at 12:19 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 19562" data-quote="ohwilleke" data-source="post: 7078406" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> ohwilleke said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> The headline of the OP is a bit misleading. Scientists have proposed ways to test if reality is closer to the LQG or the classical GR prediction. But, nobody has actually done those tests at the level of precision necessary to actually distinguish between the two theories with any meaningful statistical significance. </div> </div> </blockquote><br /> what do you think of strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA*as a way to test quantum gravity effects ?<br /> <br /> does string theory make any predictions of strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA*?<br /> <br /> could quantum gravity effects show up as strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA*</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="weirdoguy" data-content="post-7078531" id="js-post-7078531" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7078531/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7078531"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-04-16T02:56:20-0500" data-time="1713254180" data-date-string="Apr 16, 2024" data-time-string="2:56 AM" title="Apr 16, 2024 at 2:56 AM" itemprop="datePublished">Apr 16, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7078531/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #5 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/weirdoguy.464738/"> <meta itemprop="url" content="https://www.physicsforums.com/members/weirdoguy.464738/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="464738"><span itemprop="name">weirdoguy</span></span></span>     </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,167</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>1,123</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7078531" data-lb-caption-desc="weirdoguy · Apr 16, 2024 at 2:56 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 551353" data-quote="kodama" data-source="post: 7078515" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> kodama said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> what do you think </div> </div> </blockquote><br /> What do <b>you</b> think?</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="3" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--1" data-reaction-id="1"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Like" title="Like" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>ohwilleke</bdi>, <bdi>berkeman</bdi> and <bdi>pines-demon</bdi> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="ohwilleke" data-content="post-7078727" id="js-post-7078727" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7078727/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7078727"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-04-16T14:50:56-0500" data-time="1713297056" data-date-string="Apr 16, 2024" data-time-string="2:50 PM" title="Apr 16, 2024 at 2:50 PM" itemprop="datePublished">Apr 16, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7078727/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #6 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/ohwilleke.19562/"> <meta itemprop="url" content="https://www.physicsforums.com/members/ohwilleke.19562/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="19562"><span itemprop="name">ohwilleke</span></span></span>    <div class="post-badges"> <div class="post-badge badge-star" data-xf-init="tooltip" title="Click to Support PF"> <i class="fa--xf fal fa-star" aria-hidden="true"></i><span> Gold Member</span> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>2,578</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>1,530</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7078727" data-lb-caption-desc="ohwilleke · Apr 16, 2024 at 2:50 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 551353" data-quote="kodama" data-source="post: 7078515" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> kodama said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> what do you think of strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA*as a way to test quantum gravity effects ? </div> </div> </blockquote>It is a great and obvious way to test quantum gravity effects, once you have the telescopes (defined broadly to include anything that makes an astronomy observation) to do it. Since they are, by definition, at the heart of these galaxies, however, sifting through the foregrounds to observe what you really want to see is challenging.<br /> <blockquote data-attributes="member: 551353" data-quote="kodama" data-source="post: 7078515" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> kodama said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> does string theory make any predictions of strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA*? </div> </div> </blockquote>String theory makes no predictions and has no observational support. It isn't really even really a theory so much as an approach to come up with a theory that no one has managed to set forth yet.<br /> <blockquote data-attributes="member: 551353" data-quote="kodama" data-source="post: 7078515" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> kodama said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> could quantum gravity effects show up as strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA* </div> </div> </blockquote>Yes.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> <div class="message-lastEdit"> Last edited: <time class="u-dt" dir="auto" datetime="2024-04-16T16:28:37-0500" data-time="1713302917" data-date-string="Apr 16, 2024" data-time-string="4:28 PM" title="Apr 16, 2024 at 4:28 PM" itemprop="dateModified">Apr 16, 2024</time> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="2" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--1" data-reaction-id="1"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Like" title="Like" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>billtodd</bdi> and <bdi>kodama</bdi> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="kodama" data-content="post-7078790" id="js-post-7078790" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7078790/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7078790"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-04-16T20:45:31-0500" data-time="1713318331" data-date-string="Apr 16, 2024" data-time-string="8:45 PM" title="Apr 16, 2024 at 8:45 PM" itemprop="datePublished">Apr 16, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7078790/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #7 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/kodama.551353/"> <meta itemprop="url" content="https://www.physicsforums.com/members/kodama.551353/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="551353"><span itemprop="name">kodama</span></span></span>   <span class="threadstarter" data-xf-init="tooltip" title="Thread Starter"><i class="fal fa-user-edit"></i></span>   </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,026</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>139</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7078790" data-lb-caption-desc="kodama · Apr 16, 2024 at 8:45 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 19562" data-quote="ohwilleke" data-source="post: 7078727" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> ohwilleke said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> It is a great and obvious way to test quantum gravity effects, once you have the telescopes (defined broadly to include anything that makes an astronomy observation) to do it. Since they are, by definition, at the heart of these galaxies, however, sifting through the foregrounds to observe what you really want to see is challenging.<br /> <br /> String theory makes no predictions and has no observational support. It isn't really even really a theory so much as an approach to come up with a theory that no one has managed to set forth yet.<br /> <br /> Yes. </div> </div> </blockquote><br /> this<br /> arXiv:2305.04336 (gr-qc)<br /> [Submitted on 7 May 2023 (v1), last revised 30 Oct 2023 (this version, v2)]<br /> Strong Gravitational Lensing by Loop Quantum Gravity Motivated Rotating Black Holes and EHT Observations<br /> Jitendra Kumar, Shafqat Ul Islam, Sushant G. Ghosh<br /> <br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> We estimate the time delay between the first and second relativistic images using twenty supermassive galactic centre black holes as lenses. Our analysis concludes that, within the 1σ region, a significant portion of the BH-I and BH-II and for a small portion of BH-III parameter space agrees with the EHT results of M87* and Sgr A* whereas NH is completely ruled out. We discover that the EHT results of Sgr A* place more stringent limits on the parameter space of LMRBH black holes than those established by the EHT results of M87*. </div> </div> </blockquote><br /> . Our analysis concludes that, within the 1σ region, perhaps 5σ might be measured in more advanced degree with better quality telescopes<br /> <br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> String theory makes no predictions and has no observational support. It isn't really even really a theory so much as an approach to come up with a theory that no one has managed to set forth yet. </div> </div> </blockquote><br /> String theory predicts massless spin 2, identify with the gravitons<br /> <br /> gravitons in qft is a type of quantum gravity<br /> <br /> does gravitons spin 2 in qft or super gravity quantum gravity effects show up as strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA*?<br /> <br /> <br /> if successful loop quantum gravity theory 5σ quantum gravity effects show up as strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA* could other quantum gravity theory reproduce the same results</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> <div class="message-lastEdit"> Last edited: <time class="u-dt" dir="auto" datetime="2024-04-16T20:55:10-0500" data-time="1713318910" data-date-string="Apr 16, 2024" data-time-string="8:55 PM" title="Apr 16, 2024 at 8:55 PM" itemprop="dateModified">Apr 16, 2024</time> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--5" data-reaction-id="5"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Sad" title="Sad" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>weirdoguy</bdi> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="kodama" data-content="post-7080508" id="js-post-7080508" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7080508/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7080508"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-04-22T09:01:45-0500" data-time="1713794505" data-date-string="Apr 22, 2024" data-time-string="9:01 AM" title="Apr 22, 2024 at 9:01 AM" itemprop="datePublished">Apr 22, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7080508/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #8 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/kodama.551353/"> <meta itemprop="url" content="https://www.physicsforums.com/members/kodama.551353/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="551353"><span itemprop="name">kodama</span></span></span>   <span class="threadstarter" data-xf-init="tooltip" title="Thread Starter"><i class="fal fa-user-edit"></i></span>   </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,026</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>139</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7080508" data-lb-caption-desc="kodama · Apr 22, 2024 at 9:01 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">arXiv:2404.12811 (gr-qc)<br /> [Submitted on 19 Apr 2024]<br /> Black Hole shadows of α′-corrected black holes<br /> F. Agurto-Sepúlveda, J. Oliva, M. Oyarzo, D.R.G Schleicher<br /> <br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> In this paper we study the qualitative features induces by corrections to GR coming from String Theory, on the shadows of rotating black holes. We deal with the slowly rotating black hole solutions up to order O(a3), to first order in α′, including also the dilaton. We provide a detailed characterization of the geometry, as well as the ISCO and photon ring, and then we proceed to obtain the black hole images within the relativistic thin-disk model. We characterize the images by computing the diameter, displacement and asymmetry. A comparison with the Kerr case, indicates that all these quantities grow due to the α′ correction, and that the departure from GR for different observable is enhanced depending on the angle of view, namely for the diameter the maximum departure is obtained when the system is face-on, while for the displacement and asymmetry the departure from GR is maximized for edge-on point of view.<br /> <br /> Comments: 14 pages, 8 figures<br /> Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)<br /> Cite as: arXiv:2404.12811 [gr-qc]<br /> (or arXiv:2404.12811v1 [gr-qc] for this version) </div> </div> </blockquote><br /> "corrections to GR coming from String Theory, on the shadows of rotating black holes" vs "gravitational lensing in the strong deflection regime by loop quantum gravity (LQG)-motivated rotating black hole"<br /> <br /> "In this paper, we calculate the strong/weak gravitational lensing effects under the quantum-corrected black hole model, taking the supermassive black holes M87* and SgrA* as the subjects of study to explore the impact of the quantum correction parameter α on the positions of images and the Einstein ring."<br /> <br /> vs<br /> "In this paper we study the qualitative features induces by corrections to GR coming from String Theory, on the shadows of rotating black holes. We deal with the slowly rotating black hole solutions up to order O(a3), to first order in α′, including also the dilaton. We provide a detailed characterization of the geometry, as well as the ISCO and photon ring,"<br /> <br /> similar to lqg<br /> both papers on quantum corrections to GR , on the shadows of rotating black holes<br /> <br /> would be interested to compare quantum corrections to GR coming from String Theory, on the shadows of rotating black holes with loop quantum gravity (LQG)-motivated rotating black hole strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA* with real world observations</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> <div class="message-lastEdit"> Last edited: <time class="u-dt" dir="auto" datetime="2024-04-22T13:33:57-0500" data-time="1713810837" data-date-string="Apr 22, 2024" data-time-string="1:33 PM" title="Apr 22, 2024 at 1:33 PM" itemprop="dateModified">Apr 22, 2024</time> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="Vanadium 50" data-content="post-7080525" id="js-post-7080525" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7080525/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7080525"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-04-22T09:41:37-0500" data-time="1713796897" data-date-string="Apr 22, 2024" data-time-string="9:41 AM" title="Apr 22, 2024 at 9:41 AM" itemprop="datePublished">Apr 22, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7080525/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #9 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/vanadium-50.110252/"> <meta itemprop="url" content="https://www.physicsforums.com/members/vanadium-50.110252/" /> <div class="message-userDetails"> <span class="message-name"><a href="/members/vanadium-50.110252/" class="username " dir="auto" data-user-id="110252" data-xf-init="member-tooltip"><span itemprop="name">Vanadium 50</span></a></span>    <div class="post-badges"> <div class="post-badge badge-shield" data-xf-init="tooltip" title="Retired Mentor"> <i class="fa--xf fal fa-shield" aria-hidden="true" style="font-size:12px;color:#990033;"></i><span> Staff Emeritus</span> </div> <div class="post-badge badge-university" data-xf-init="tooltip" title="Verified Expert in Science and Math"> <i class="fa--xf fal fa-university" aria-hidden="true"></i><span> Science Advisor</span> </div> <div class="post-badge badge-book" data-xf-init="tooltip" title="Verified Expert in Academia"> <i class="fa--xf fal fa-book" aria-hidden="true"></i><span> Education Advisor</span> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>35,001</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>21,677</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7080525" data-lb-caption-desc="Vanadium 50 · Apr 22, 2024 at 9:41 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 551353" data-quote="kodama" data-source="post: 7080508" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> kodama said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> similar to lqg </div> </div> </blockquote>In that both can be printed on A4 paper, yes.<br /> <br /> You keep pointing us to papers that do not say what you say they do. You did it with the X17 and you're doing it now. It is more than a little annoying.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="1" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--1" data-reaction-id="1"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Like" title="Like" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>ShadowKraz</bdi> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="kodama" data-content="post-7080728" id="js-post-7080728" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7080728/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7080728"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-04-22T21:29:16-0500" data-time="1713839356" data-date-string="Apr 22, 2024" data-time-string="9:29 PM" title="Apr 22, 2024 at 9:29 PM" itemprop="datePublished">Apr 22, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7080728/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #10 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/kodama.551353/"> <meta itemprop="url" content="https://www.physicsforums.com/members/kodama.551353/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="551353"><span itemprop="name">kodama</span></span></span>   <span class="threadstarter" data-xf-init="tooltip" title="Thread Starter"><i class="fal fa-user-edit"></i></span>   </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,026</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>139</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7080728" data-lb-caption-desc="kodama · Apr 22, 2024 at 9:29 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">of interest <br /> <br /> arXiv:2403.09756 (gr-qc)<br /> [Submitted on 14 Mar 2024 (v1), last revised 21 Apr 2024 (this version, v2)]<br /> Signatures of the accelerating black holes with a cosmological constant from the Sgr~A⋆ and M87⋆ shadow prospects<br /> L. Chakhchi, H. El Moumni, K. Masmar<br /> <br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> Recently, the Event Horizon Telescope (EHT) achieved the realization of an image of the supermassive black hole Sgr~A⋆ showing an angular shadow diameter D=48.7±7μas and the fractional deviation δ=−0.08+0.09−0.09 (VLTI),−0.04+0.09−0.10 (Keck), alongside the earlier image of M87⋆ with angular diameter D=42±3μas, deviation δ=−0.01+0.17−0.17 and deviations from circularity estimated to be ΔC≲10%. In addition, the shadow radii are assessed within the ranges 3.38≤rsM≤6.91 for M87⋆ and 3.85≤rsM≤5.72 as well as 3.95≤rsM≤5.92 for Sgr~A⋆ using the Very Large Telescope Interferometer (VLTI) and Keck observatories, respectively. These values are provided with 1-σ and 2-σ measurements. Such realizations can unveil a better comprehension of gravitational physics at the horizon scale. In this paper, we use the EHT observational results for M87⋆ and Sgr~A⋆ to elaborate the constraints on parameters of accelerating black holes with a cosmological constant. Concretely, we utilize the mass and distance of both black holes to derive the observables associated with the accelerating black hole shadow. First, we compare our findings with observed quantities such as angular diameter, circularity, shadow radius, and the fractional deviation from the M87⋆ data. This comparison reveals constraints within the acceleration parameter and the cosmological constant...<br /> Lastly, one cannot rule out the possibility of the negative values for the cosmological constant on the emergence of accelerated black hole solutions within the context of minimal gauged supergravity... <br /> <br /> Comments: 37 pages, 10 figures, references updated<br /> Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)<br /> Cite as: arXiv:2403.09756 [gr-qc]<br /> (or arXiv:2403.09756v2 [gr-qc] for this version)<br /> <br /> <a href="https://doi.org/10.48550/arXiv.2403.09756" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://doi.org/10.48550/arXiv.2403.09756</a><br /> Journal reference: Physics of the Dark Universe 44 (2024) 101501<br /> Related DOI: <br /> <a href="https://doi.org/10.1016/j.dark.2024.101501" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://doi.org/10.1016/j.dark.2024.101501</a> </div> </div> </blockquote></div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="ShadowKraz" data-content="post-7094406" id="js-post-7094406" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7094406/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7094406"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-06-07T11:35:04-0500" data-time="1717778104" data-date-string="Jun 7, 2024" data-time-string="11:35 AM" title="Jun 7, 2024 at 11:35 AM" itemprop="datePublished">Jun 7, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7094406/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #11 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/shadowkraz.747904/"> <meta itemprop="url" content="https://www.physicsforums.com/members/shadowkraz.747904/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="747904"><span itemprop="name">ShadowKraz</span></span></span>     </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>54</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>32</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7094406" data-lb-caption-desc="ShadowKraz · Jun 7, 2024 at 11:35 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 110252" data-quote="Vanadium 50" data-source="post: 7080525" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> Vanadium 50 said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> In that both can be printed on A4 paper, yes.<br /> <br /> You keep pointing us to papers that do not say what you say they do. You did it with the X17 and you're doing it now. It is more than a little annoying. </div> </div> </blockquote>It seems the OP is more confused, possibly on a higher level, about these things than I am.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="kodama" data-content="post-7114440" id="js-post-7114440" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7114440/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7114440"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-08-21T22:00:56-0500" data-time="1724295656" data-date-string="Aug 21, 2024" data-time-string="10:00 PM" title="Aug 21, 2024 at 10:00 PM" itemprop="datePublished">Aug 21, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7114440/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #12 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/kodama.551353/"> <meta itemprop="url" content="https://www.physicsforums.com/members/kodama.551353/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="551353"><span itemprop="name">kodama</span></span></span>   <span class="threadstarter" data-xf-init="tooltip" title="Thread Starter"><i class="fal fa-user-edit"></i></span>   </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,026</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>139</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7114440" data-lb-caption-desc="kodama · Aug 21, 2024 at 10:00 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">arXiv:2408.11603 [pdf, html, other]<br /> Gravitational lensing effect of black holes in effective quantum gravity<br /> Hao Liu, Meng-Yun Lai, Xiao-Yin Pan, Hyat Huang, De-Cheng Zou<br /> Subjects: General Relativity and Quantum Cosmology (gr-qc) <br /> <br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> In the present work, we investigate the gravitational lensing effects of two quantum-modified black hole models recently proposed in effective quantum gravity. The light deflection angles in both the weak field limit and the strong field limit are calculated. Furthermore, we use the data of the supermassive black holes SgrA* and M87* and calculate the lensing observables in the strong field limit. We find that the quantum parameter plays a role analogous to the electric charge in the weak gravitational lensing, whereas in the strong field limit, the effect of the quantum parameter on the deflection angle, the angular separation and the relative magnification is opposite to that of the electric charge, the scalar charge and the quantum parameters in some gravity theories. The results indicate the discrepancies between the classical black holes and the two quantum-modified black hole models that depend on the quantum correction, making them a valuable tool for differentiating between these black hole models. </div> </div> </blockquote></div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="kodama" data-content="post-7118520" id="js-post-7118520" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7118520/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7118520"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-09-09T23:33:28-0500" data-time="1725942808" data-date-string="Sep 9, 2024" data-time-string="11:33 PM" title="Sep 9, 2024 at 11:33 PM" itemprop="datePublished">Sep 9, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7118520/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #13 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/kodama.551353/"> <meta itemprop="url" content="https://www.physicsforums.com/members/kodama.551353/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="551353"><span itemprop="name">kodama</span></span></span>   <span class="threadstarter" data-xf-init="tooltip" title="Thread Starter"><i class="fal fa-user-edit"></i></span>   </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,026</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>139</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7118520" data-lb-caption-desc="kodama · Sep 9, 2024 at 11:33 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">Submitted on 9 Sep 2024]<br /> Gravitational lensing and shadows from thin-disks in Loop Quantum Gravity self-dual black holes<br /> David J. Patiño Pomares, Diego Rubiera-Garcia<br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> We analyze gravitational lensing and their cast images from thin-disks in shadow observations of a family of spherically symmetric black hole solutions previously derived within the framework of Loop Quantum Gravity. Such black holes depend on two parameters (besides the mass of the black hole itself), P and a0, the latter imbuing the configurations with an interior wormhole structure. Using the bounds from the Event Horizon Telescope regarding the shadow's radius of Sgr A∗ that constrain the parameter P≲0.08(2σ) (at a0=0), we study the modifications to weak and strong gravitational lensing induced by these geometries as compared to the Schwarzschild black hole within this range. In particular, we discuss several observables in the strong field regime related to the luminosity decay, the angular separation, and the flux ratio between multiples images of the source. Furthermore, we consider the cast images of these black holes when illuminated by a geometrically and optically thin accretion disk according to several semi-analytic profiles for the disk's emission. <br /> <br /> Comments: 12 pages, 6 figures<br /> Subjects: General Relativity and Quantum Cosmology (gr-qc)<br /> Cite as: arXiv:2409.05371 [gr-qc]<br /> (or arXiv:2409.05371v1 [gr-qc] for this version)<br /> <br /> <a href="https://doi.org/10.48550/arXiv.2409.05371" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://doi.org/10.48550/arXiv.2409.05371</a> </div> </div> </blockquote></div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="kodama" data-content="post-7118789" id="js-post-7118789" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7118789/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7118789"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-09-11T14:09:02-0500" data-time="1726081742" data-date-string="Sep 11, 2024" data-time-string="2:09 PM" title="Sep 11, 2024 at 2:09 PM" itemprop="datePublished">Sep 11, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7118789/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #14 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/kodama.551353/"> <meta itemprop="url" content="https://www.physicsforums.com/members/kodama.551353/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="551353"><span itemprop="name">kodama</span></span></span>   <span class="threadstarter" data-xf-init="tooltip" title="Thread Starter"><i class="fal fa-user-edit"></i></span>   </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,026</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>139</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7118789" data-lb-caption-desc="kodama · Sep 11, 2024 at 2:09 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">arXiv:2409.05897 (gr-qc)<br /> [Submitted on 5 Sep 2024]<br /> Gravitational lensing in holonomy corrected spherically symmetric black holes with phantom global monopoles<br /> Faizuddin Ahmed<br /> <br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> In this paper, we address a theoretical investigation of the gravitational lensing phenomenon within the space-time framework of a holonomy-corrected spherically symmetric black hole (BH), incorporating both ordinary and phantom global monopoles. Our focus lies on the analysis of null geodesics within this black hole background, examining the influence of ordinary and phantom global monopoles on the effective potential of null geodesics of the system. Afterwards, we derive analytical expressions for the deflection angle of photon light, considering weak field limit. The obtain expressions are presented up to the second order of the Loop Quantum Gravity parameter, enabling a thorough examination of the impact of ordinary and phantom global monopoles on the deflection angle. <br /> <br /> Comments: 12 pages, 3 figures, accepted in IJGMMP (this https URL)<br /> Subjects: General Relativity and Quantum Cosmology (gr-qc)<br /> Cite as: arXiv:2409.05897 [gr-qc]<br /> (or arXiv:2409.05897v1 [gr-qc] for this version)<br /> <br /> <a href="https://doi.org/10.48550/arXiv.2409.05897" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://doi.org/10.48550/arXiv.2409.05897</a> </div> </div> </blockquote></div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="kodama" data-content="post-7119049" id="js-post-7119049" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7119049/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7119049"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-09-12T22:22:52-0500" data-time="1726197772" data-date-string="Sep 12, 2024" data-time-string="10:22 PM" title="Sep 12, 2024 at 10:22 PM" itemprop="datePublished">Sep 12, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7119049/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #15 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/kodama.551353/"> <meta itemprop="url" content="https://www.physicsforums.com/members/kodama.551353/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="551353"><span itemprop="name">kodama</span></span></span>   <span class="threadstarter" data-xf-init="tooltip" title="Thread Starter"><i class="fal fa-user-edit"></i></span>   </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,026</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>139</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7119049" data-lb-caption-desc="kodama · Sep 12, 2024 at 10:22 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">Submitted on 12 Sep 2024]<br /> Probing Quantum Gravity Effects with Eccentric Extreme Mass-Ratio Inspirals<br /> Guoyang Fu, Yunqi Liu, Bin Wang, Jian-Pin Wu, Chao Zhang<br /> <br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> In this paper, we investigate the impact of loop quantum gravity (LQG) on extreme mass-ratio inspirals (EMRIs), and the results indicate that LQG effects cause the orbital decay to occur faster compared to the Schwarzschild case. Furthermore, we use the augmented analytic kludge approach to generate EMRI waveforms and study the LISA's capability to detect the LQG effect with faithfulness. Additionally, employing the Fisher information matrix method for parameter estimation, we estimate that after one year of observation, the uncertainty in r0 reduces to approximately 6.59×10−4 with a signal-to-noise ratio of 49. <br /> <br /> Comments: 22 pages,7 figures<br /> Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)<br /> Cite as: arXiv:2409.08138 [gr-qc]<br /> (or arXiv:2409.08138v1 [gr-qc] for this version)<br /> <br /> <a href="https://doi.org/10.48550/arXiv.2409.08138" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://doi.org/10.48550/arXiv.2409.08138</a> </div> </div> </blockquote></div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="jedishrfu" data-content="post-7119207" id="js-post-7119207" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7119207/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/" /> <span class="u-anchorTarget" id="post-7119207"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-09-13T17:22:25-0500" data-time="1726266145" data-date-string="Sep 13, 2024" data-time-string="5:22 PM" title="Sep 13, 2024 at 5:22 PM" itemprop="datePublished">Sep 13, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7119207/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #16 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/jedishrfu.376845/"> <meta itemprop="url" content="https://www.physicsforums.com/members/jedishrfu.376845/" /> <div class="message-userDetails"> <span class="message-name"><a href="/members/jedishrfu.376845/" class="username " dir="auto" data-user-id="376845" data-xf-init="member-tooltip"><span class="username--staff username--moderator" itemprop="name">jedishrfu</span></a></span>    <div class="post-badges"> <div class="post-badge badge-mentor" data-xf-init="tooltip" title="PF Community Staff"> <i class="fa--xf fal fa-user-graduate" aria-hidden="true"></i><span> Mentor</span> </div> <div class="post-badge badge-file" data-xf-init="tooltip" title="Click to View My Articles"> <a href="https://www.physicsforums.com/insights/author/jedishrfu/"><i class="fa--xf fal fa-file-alt" aria-hidden="true"></i><span> Insights Author</span></a> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>15,164</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>9,748</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7119207" data-lb-caption-desc="jedishrfu · Sep 13, 2024 at 5:22 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">Since very few people post here except for abstract after abstract after abstract from the OP, it seems that its a good time to close this thread.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="4" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--1" data-reaction-id="1"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Like" title="Like" /></span></li><li><span class="reaction reaction--small reaction--2" data-reaction-id="2"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Love" title="Love" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>weirdoguy</bdi>, <bdi>phinds</bdi>, <bdi>Vanadium 50</bdi> and 1 other person </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> <script> if (typeof parseNewPost == 'function') { $(document).ajaxStop(parseNewPost(7119207)); } </script> </div> </div> </div> </article> </div> </div> </div> <div class="block" data-widget-id="119" data-widget-key="xfes_thread_view_below_quick_reply_similar_threads" data-widget-definition="xfes_similar_threads"> <div class="block-container"> <h3 class="block-header">Similar threads</h3> <div class="block-body"> <div class="structItemContainer"> <div class="structItem structItem--thread is-prefix91 js-inlineModContainer js-threadListItem-1065273" data-author="kodama"> <div class="structItem-cell structItem-cell--main" data-xf-init="touch-proxy"> <div class="structItem-title"> <span class="prefix inter" dir="auto">I</span> <a href="/threads/unifying-string-theory-and-loop-quantum-gravity.1065273/" class="" data-tp-primary="on" data-xf-init="preview-tooltip" data-preview-url="/threads/unifying-string-theory-and-loop-quantum-gravity.1065273/preview">Unifying string theory and loop quantum gravity</a> </div> <div class="structItem-minor"> <ul class="structItem-parts"> <li class="structItem-startDate"><time class="structItem-latestDate u-dt" dir="auto" datetime="2024-09-08T00:22:08-0500" data-time="1725772928" data-date-string="Sep 8, 2024" data-time-string="12:22 AM" title="Sep 8, 2024 at 12:22 AM">Sep 8, 2024</time></li>  </ul> <ul class="structItem-parts"> </ul> </div> </div> <div class="structItem-cell structItem-cell--meta" title="First message reaction score: 1"> <dl class="pairs pairs--justified"> <dt>Replies</dt> <dd>2</dd> </dl> <dl class="pairs pairs--justified structItem-minor"> <dt>Views</dt> <dd>1K</dd> </dl> </div> </div> <div class="structItem structItem--thread is-prefix91 js-inlineModContainer js-threadListItem-1056202" data-author="kodama"> <div class="structItem-cell structItem-cell--main" data-xf-init="touch-proxy"> <div class="structItem-title"> <span class="prefix inter" dir="auto">I</span> <a href="/threads/is-loop-quantum-gravity-dual-to-cft.1056202/" class="" data-tp-primary="on" data-xf-init="preview-tooltip" data-preview-url="/threads/is-loop-quantum-gravity-dual-to-cft.1056202/preview">Is loop quantum gravity dual to CFT?</a> </div> <div class="structItem-minor"> <ul class="structItem-parts"> <li class="structItem-startDate"><time class="structItem-latestDate u-dt" dir="auto" datetime="2023-11-01T23:08:24-0500" data-time="1698898104" data-date-string="Nov 1, 2023" data-time-string="11:08 PM" title="Nov 1, 2023 at 11:08 PM">Nov 1, 2023</time></li>  </ul> <ul class="structItem-parts"> </ul> </div> </div> <div class="structItem-cell structItem-cell--meta" title="First message reaction score: 0"> <dl class="pairs pairs--justified"> <dt>Replies</dt> <dd>13</dd> </dl> <dl class="pairs pairs--justified structItem-minor"> <dt>Views</dt> <dd>3K</dd> </dl> </div> </div> <div class="structItem structItem--thread is-prefix91 is-locked js-inlineModContainer js-threadListItem-1064864" data-author="kodama"> <div class="structItem-cell structItem-cell--main" data-xf-init="touch-proxy"> <div class="structItem-title"> <span class="prefix inter" dir="auto">I</span> <a href="/threads/the-standard-model-from-loop-quantum-gravity-via-spinors-octonions.1064864/" class="" data-tp-primary="on" data-xf-init="preview-tooltip" data-preview-url="/threads/the-standard-model-from-loop-quantum-gravity-via-spinors-octonions.1064864/preview">The standard model from loop quantum gravity via spinors octonions</a> </div> <div class="structItem-minor"> <ul class="structItem-parts"> <li class="structItem-startDate"><time class="structItem-latestDate u-dt" dir="auto" datetime="2024-10-08T22:13:35-0500" data-time="1728443615" data-date-string="Oct 8, 2024" data-time-string="10:13 PM" title="Oct 8, 2024 at 10:13 PM">Oct 8, 2024</time></li>  </ul> <ul class="structItem-parts"> </ul> </div> </div> <div class="structItem-cell structItem-cell--meta" title="First message reaction score: 0"> <dl class="pairs pairs--justified"> <dt>Replies</dt> <dd>26</dd> </dl> <dl class="pairs pairs--justified structItem-minor"> <dt>Views</dt> <dd>2K</dd> </dl> </div> </div> <div class="structItem structItem--thread is-prefix91 is-locked js-inlineModContainer js-threadListItem-992044" data-author="ohwilleke"> <div class="structItem-cell structItem-cell--main" data-xf-init="touch-proxy"> <div class="structItem-title"> <span class="prefix inter" dir="auto">I</span> <a href="/threads/trouble-for-loop-quantum-gravity.992044/" class="" data-tp-primary="on" data-xf-init="preview-tooltip" data-preview-url="/threads/trouble-for-loop-quantum-gravity.992044/preview">Trouble for Loop Quantum Gravity?</a> </div> <div class="structItem-minor"> <ul class="structItem-parts"> <li class="structItem-startDate"><time class="structItem-latestDate u-dt" dir="auto" datetime="2020-08-16T11:05:33-0500" data-time="1597593933" data-date-string="Aug 16, 2020" data-time-string="11:05 AM" title="Aug 16, 2020 at 11:05 AM">Aug 16, 2020</time></li>  </ul> <ul class="structItem-parts"> </ul> </div> </div> <div class="structItem-cell structItem-cell--meta" title="First message reaction score: 4"> <dl class="pairs pairs--justified"> <dt>Replies</dt> <dd>3</dd> </dl> <dl class="pairs pairs--justified structItem-minor"> <dt>Views</dt> <dd>2K</dd> </dl> </div> </div> <div class="structItem structItem--thread is-prefix91 js-inlineModContainer js-threadListItem-1053691" data-author="kodama"> <div class="structItem-cell structItem-cell--main" data-xf-init="touch-proxy"> <div class="structItem-title"> <span class="prefix inter" dir="auto">I</span> <a href="/threads/wittens-paper-a-note-on-the-canonical-formalism-for-gravity-lqg.1053691/" class="" data-tp-primary="on" data-xf-init="preview-tooltip" data-preview-url="/threads/wittens-paper-a-note-on-the-canonical-formalism-for-gravity-lqg.1053691/preview">Witten’s paper: "A Note On The Canonical Formalism for Gravity" LQG</a> </div> <div class="structItem-minor"> <ul class="structItem-parts"> <li class="structItem-startDate"><time class="structItem-latestDate u-dt" dir="auto" datetime="2024-03-14T03:13:01-0500" data-time="1710403981" data-date-string="Mar 14, 2024" data-time-string="3:13 AM" title="Mar 14, 2024 at 3:13 AM">Mar 14, 2024</time></li>  </ul> <ul class="structItem-parts"> </ul> </div> </div> <div class="structItem-cell structItem-cell--meta" title="First message reaction score: 1"> <dl class="pairs pairs--justified"> <dt>Replies</dt> <dd>13</dd> </dl> <dl class="pairs pairs--justified structItem-minor"> <dt>Views</dt> <dd>4K</dd> </dl> </div> </div> <div class="structItem structItem--thread is-prefix91 js-inlineModContainer js-threadListItem-1054316" data-author="kodama"> <div class="structItem-cell structItem-cell--main" data-xf-init="touch-proxy"> <div class="structItem-title"> <span class="prefix inter" dir="auto">I</span> <a href="/threads/ads-cft-and-ashtekar-variables-or-spinfoam.1054316/" class="" data-tp-primary="on" data-xf-init="preview-tooltip" data-preview-url="/threads/ads-cft-and-ashtekar-variables-or-spinfoam.1054316/preview">Ads/CFT and Ashtekar variables or spinfoam</a> </div> <div class="structItem-minor"> <ul class="structItem-parts"> <li class="structItem-startDate"><time class="structItem-latestDate u-dt" dir="auto" datetime="2023-08-02T15:38:40-0500" data-time="1691008720" data-date-string="Aug 2, 2023" data-time-string="3:38 PM" title="Aug 2, 2023 at 3:38 PM">Aug 2, 2023</time></li>  </ul> <ul class="structItem-parts"> </ul> </div> </div> <div class="structItem-cell structItem-cell--meta" title="First message reaction score: 1"> <dl class="pairs pairs--justified"> <dt>Replies</dt> <dd>7</dd> </dl> <dl class="pairs pairs--justified structItem-minor"> <dt>Views</dt> <dd>2K</dd> </dl> </div> </div> <div class="structItem structItem--thread is-prefix91 js-inlineModContainer js-threadListItem-1017550" data-author="kodama"> <div class="structItem-cell structItem-cell--main" data-xf-init="touch-proxy"> <div class="structItem-title"> <span class="prefix inter" dir="auto">I</span> <a href="/threads/noncommutative-geometry-and-asymptotic-safe-gravity-and-mond.1017550/" class="" data-tp-primary="on" data-xf-init="preview-tooltip" data-preview-url="/threads/noncommutative-geometry-and-asymptotic-safe-gravity-and-mond.1017550/preview">Noncommutative geometry and asymptotic safe gravity and MOND</a> </div> <div class="structItem-minor"> <ul class="structItem-parts"> <li class="structItem-startDate"><time class="structItem-latestDate u-dt" dir="auto" datetime="2022-08-13T15:53:06-0500" data-time="1660423986" data-date-string="Aug 13, 2022" data-time-string="3:53 PM" title="Aug 13, 2022 at 3:53 PM">Aug 13, 2022</time></li>  </ul> <ul class="structItem-parts"> </ul> </div> </div> <div class="structItem-cell structItem-cell--meta" title="First message reaction score: 1"> <dl class="pairs pairs--justified"> <dt>Replies</dt> <dd>3</dd> </dl> <dl class="pairs pairs--justified structItem-minor"> <dt>Views</dt> <dd>2K</dd> </dl> </div> </div> <div class="structItem structItem--thread is-prefix92 js-inlineModContainer js-threadListItem-1067526" data-author="mitchell porter"> <div class="structItem-cell structItem-cell--main" data-xf-init="touch-proxy"> <div class="structItem-title"> <span class="prefix advanced" dir="auto">A</span> <a href="/threads/shahar-hods-bound-on-the-fine-structure-constant.1067526/" class="" data-tp-primary="on" data-xf-init="preview-tooltip" data-preview-url="/threads/shahar-hods-bound-on-the-fine-structure-constant.1067526/preview">Shahar Hod's bound on the fine-structure constant</a> </div> <div class="structItem-minor"> <ul class="structItem-parts"> <li class="structItem-startDate"><time class="structItem-latestDate u-dt" dir="auto" datetime="2025-02-12T15:35:00-0600" data-time="1739396100" data-date-string="Feb 12, 2025" data-time-string="3:35 PM" title="Feb 12, 2025 at 3:35 PM">Feb 12, 2025</time></li>  </ul> <ul class="structItem-parts"> </ul> </div> </div> <div class="structItem-cell structItem-cell--meta" title="First message reaction score: 1"> <dl class="pairs pairs--justified"> <dt>Replies</dt> <dd>10</dd> </dl> <dl class="pairs pairs--justified structItem-minor"> <dt>Views</dt> <dd>1K</dd> </dl> </div> </div> <div class="structItem structItem--thread is-locked js-inlineModContainer js-threadListItem-845846" data-author="kodama"> <div class="structItem-cell structItem-cell--main" data-xf-init="touch-proxy"> <div class="structItem-title"> <a href="/threads/recent-papers-on-self-dual-loop-quantum-black-holes.845846/" class="" data-tp-primary="on" data-xf-init="preview-tooltip" data-preview-url="/threads/recent-papers-on-self-dual-loop-quantum-black-holes.845846/preview">Recent papers on self-dual loop quantum black holes</a> </div> <div class="structItem-minor"> <ul class="structItem-parts"> <li class="structItem-startDate"><time class="structItem-latestDate u-dt" dir="auto" datetime="2016-01-20T19:29:26-0600" data-time="1453339766" data-date-string="Jan 20, 2016" data-time-string="7:29 PM" title="Jan 20, 2016 at 7:29 PM">Jan 20, 2016</time></li>  </ul> <ul class="structItem-parts"> </ul> </div> </div> <div class="structItem-cell structItem-cell--meta" title="First message reaction score: 3"> <dl class="pairs pairs--justified"> <dt>Replies</dt> <dd>28</dd> </dl> <dl class="pairs pairs--justified structItem-minor"> <dt>Views</dt> <dd>4K</dd> </dl> </div> </div> <div class="structItem structItem--thread is-prefix91 js-inlineModContainer js-threadListItem-1065060" data-author="kodama"> <div class="structItem-cell structItem-cell--main" data-xf-init="touch-proxy"> <div class="structItem-title"> <span class="prefix inter" dir="auto">I</span> <a href="/threads/is-this-derivation-of-mond-from-general-relativity-plausible.1065060/" class="" data-tp-primary="on" data-xf-init="preview-tooltip" data-preview-url="/threads/is-this-derivation-of-mond-from-general-relativity-plausible.1065060/preview">Is this derivation of MOND from General Relativity plausible?</a> </div> <div class="structItem-minor"> <ul class="structItem-parts"> <li class="structItem-startDate"><time class="structItem-latestDate u-dt" dir="auto" datetime="2024-08-13T21:21:41-0500" data-time="1723602101" data-date-string="Aug 13, 2024" data-time-string="9:21 PM" title="Aug 13, 2024 at 9:21 PM">Aug 13, 2024</time></li>  </ul> <ul class="structItem-parts"> </ul> </div> </div> <div class="structItem-cell structItem-cell--meta" title="First message reaction score: 0"> <dl class="pairs pairs--justified"> <dt>Replies</dt> <dd>1</dd> </dl> <dl class="pairs pairs--justified structItem-minor"> <dt>Views</dt> <dd>1K</dd> </dl> </div> </div> </div> </div> </div> </div> <div class="blockMessage blockMessage--none"> <div class="shareButtons shareButtons--iconic" data-xf-init="share-buttons" data-page-url="" data-page-title="" data-page-desc="" data-page-image=""> <span class="shareButtons-label">Share:</span> <div class="shareButtons-buttons"> <a class="shareButtons-button shareButtons-button--share is-hidden" data-xf-init="web-share" data-title="" data-text="" data-url="" data-hide=".shareButtons-button:not(.shareButtons-button--share)"> <i aria-hidden="true"></i> <span>Share</span> </a> </div> </div> </div> <div class="p-breadcrumbs--parent p-breadcrumbs--bottom"> <ul class="p-breadcrumbs p-breadcrumbs--bottom" itemscope itemtype="https://schema.org/BreadcrumbList"> <li itemprop="itemListElement" itemscope itemtype="https://schema.org/ListItem"> <a href="https://www.physicsforums.com/" itemprop="item"> <span itemprop="name">Forums</span> </a> <meta itemprop="position" content="1" /> </li> <li itemprop="itemListElement" itemscope itemtype="https://schema.org/ListItem"> <a href="/#physics.9" itemprop="item"> <span itemprop="name">Physics</span> </a> <meta itemprop="position" content="2" /> </li> <li itemprop="itemListElement" itemscope itemtype="https://schema.org/ListItem"> <a href="/forums/beyond-the-standard-models.66/" itemprop="item"> <span itemprop="name">Beyond the Standard Models</span> </a> <meta itemprop="position" content="3" /> </li> </ul> </div> </div> </div> <div class="p-sidebarWrapper"> <div class="p-body-sidebar"> <div class="block" data-widget-id="64" data-widget-key="hotcontent" data-widget-definition="wte_thread_enhancement"> <div class="block-container"> <h3 class="block-minorHeader">Hot Threads</h3> <ul class="block-body"> <li class="block-row"> <div class="contentRow"> <div class="contentRow-main contentRow-main--close"> <a href="/threads/on-the-same-origin-of-quantum-physics-and-general-relativity.1065590/" title="On the same origin of quantum physics and general relativity" > <span class="prefix advanced" dir="auto">A</span><span class="label-append"> </span>On the same origin of quantum physics and general relativity </a> </div> </div> </li> <li class="block-row"> <div class="contentRow"> <div class="contentRow-main contentRow-main--close"> <a href="/threads/the-evaporation-of-charged-black-holes.1066882/" title="The evaporation of charged black holes" > <span class="prefix inter" dir="auto">I</span><span class="label-append"> </span>The evaporation of charged black holes </a> </div> </div> </li> <li class="block-row"> <div class="contentRow"> <div class="contentRow-main contentRow-main--close"> <a href="/threads/recent-history-of-minimal-length-scale.1065682/" title="Recent history of minimal length scale?" > <span class="prefix advanced" dir="auto">A</span><span class="label-append"> </span>Recent history of minimal length scale? </a> </div> </div> </li> <li class="block-row"> <div class="contentRow"> <div class="contentRow-main contentRow-main--close"> <a href="/threads/should-the-third-term-in-equation-3-11-18-be-multiplied-by-half.1066491/" title="Should the third term in equation (3.11.18) be multiplied by half?" > <span class="prefix inter" dir="auto">I</span><span class="label-append"> </span>Should the third term in equation (3.11.18) be multiplied by half? </a> </div> </div> </li> <li class="block-row"> <div class="contentRow"> <div class="contentRow-main contentRow-main--close"> <a href="/threads/shahar-hods-bound-on-the-fine-structure-constant.1067526/" title="Shahar Hod's bound on the fine-structure constant" > <span class="prefix advanced" dir="auto">A</span><span class="label-append"> </span>Shahar Hod's bound on the fine-structure constant </a> </div> </div> </li> </ul> </div> </div> <div class="block" data-widget-id="67" data-widget-key="recent_insights" data-widget-definition="wte_thread_enhancement"> <div class="block-container"> <h3 class="block-minorHeader">Recent Insights</h3> <ul class="block-body"> <li class="block-row"> <div class="contentRow"> <div class="contentRow-main contentRow-main--close"> <a href="/threads/groups-the-path-from-a-simple-concept-to-mysterious-results.1078366/" title="Groups, The Path from a Simple Concept to Mysterious Results" > <span class="prefix insight" dir="auto">Insights</span><span class="label-append"> </span>Groups, The Path from a Simple Concept to Mysterious Results </a> </div> </div> </li> <li class="block-row"> <div class="contentRow"> <div class="contentRow-main contentRow-main--close"> <a href="/threads/a-possible-ai-modern-video-codec.1078212/" title="A Possible AI Modern Video Codec" > <span class="prefix insight" dir="auto">Insights</span><span class="label-append"> </span>A Possible AI Modern Video Codec </a> </div> </div> </li> <li class="block-row"> <div class="contentRow"> <div class="contentRow-main contentRow-main--close"> <a href="/threads/beyond-the-tidal-bulge.1067812/" title="Beyond the Tidal Bulge" > <span class="prefix insight" dir="auto">Insights</span><span class="label-append"> </span>Beyond the Tidal Bulge </a> </div> </div> </li> <li class="block-row"> <div class="contentRow"> <div class="contentRow-main contentRow-main--close"> <a href="/threads/the-many-faces-of-topology.1067326/" title="The Many Faces of Topology" > <span class="prefix insight" dir="auto">Insights</span><span class="label-append"> </span>The Many Faces of Topology </a> </div> </div> </li> <li class="block-row"> <div class="contentRow"> <div class="contentRow-main contentRow-main--close"> <a href="/threads/brownian-motions-and-quantifying-randomness-in-physical-systems.1065302/" title="Brownian Motions and Quantifying Randomness in Physical Systems" > <span class="prefix insight" dir="auto">Insights</span><span class="label-append"> </span>Brownian Motions and Quantifying Randomness in Physical Systems </a> </div> </div> </li> <li class="block-row"> <div class="contentRow"> <div class="contentRow-main contentRow-main--close"> <a href="/threads/pbs-video-comment-what-if-physics-is-not-describing-reality.1064523/" title="PBS Video Comment: “What If Physics IS NOT Describing Reality”" > <span class="prefix insight" dir="auto">Insights</span><span class="label-append"> </span>PBS Video Comment: “What If Physics IS NOT Describing Reality” </a> </div> </div> </li> </ul> </div> </div> </div> </div> </div> </div> </div> </div>  <footer class="p-footer" id="footer"> <div class="p-footer--container"> <div class="p-footer-default"> <div class="p-footer-inner"> <div class="p-footer-row"> <div class="p-footer-row-main"> <ul class="p-footer-linkList"> <li class="p-linkList-changeWidth"><a class="pageWidthToggle xb-toggle-default" role="button" tabindex="0" data-xf-click="toggle" data-target="html" data-active-class="xb-toggle-default" data-xf-init="toggle-storage" data-storage-type="cookie" data-storage-expiry="31556926" data-storage-key="_xb-width"> Change width </a></li> </ul> </div> <div class="p-footer-row-opposite"> <ul class="p-footer-linkList"> <li><a href="/misc/contact">Contact</a></li> <li><a href="https://www.physicsforums.com/insights/about-physics-forums/">About</a></li> <li><a href="https://www.physicsforums.com/help/terms-of-service/">Terms</a></li> <li><a href="https://www.physicsforums.com/help/member-privacy-policy/">Privacy</a></li> <li><a href="/help/">Help</a></li> <li><a href="/forums/-/index.rss" target="_blank" class="p-footer-rssLink" title="RSS"><span aria-hidden="true"><i class="fa--xf fal fa-rss" aria-hidden="true"></i><span class="u-srOnly">RSS</span></span></a></li> </ul> </div> </div> </div> </div> <div class="p-footer-copyright"> <div class="p-footer-inner"> <div class="p-footer-copyright--flex"> <div class="copyright-left"> 2025 © Physics Forums, All Rights Reserved </div> </div> </div> </div> </div> </footer> </div>  </div>  <div class="u-bottomFixer js-bottomFixTarget"> </div> <div class="u-navButtons js-navButtons" data-trigger-type="up"> <a href="javascript:" class="button--scroll button"><span class="button-text"><i class="fa--xf fal fa-arrow-left" aria-hidden="true"></i><span class="u-srOnly">Back</span></span></a> </div> <div class="u-scrollButtons js-scrollButtons" data-trigger-type="up"> <a href="#top" class="button--scroll button" data-xf-click="scroll-to"><span class="button-text"><i class="fa--xf fal fa-arrow-up" aria-hidden="true"></i><span class="u-srOnly">Top</span></span></a> </div> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script><script>window.jQuery || document.write('<script src="/js/vendor/jquery/jquery-3.5.1.min.js?_v=bab3e795"><\/script>')</script> <script src="/js/vendor/vendor-compiled.js?_v=bab3e795"></script> <script src="/js/xf/core-compiled.js?_v=bab3e795"></script> <script> var sb=$("div.shareButtons.shareButtons--iconic");if(sb.length){var o=new IntersectionObserver(function(a){a[0].isIntersecting&&($(".has-no-fa-brands").removeClass("has-no-fa-brands"),this.disconnect())},{rootMargin:"200px"});sb.each(function(){XF.isElementVisible($(this))&&$(".has-no-fa-brands").removeClass("has-no-fa-brands");o.observe($(this)[0])})}; </script> <script> if (typeof jqProxy !== 'undefined') { jQuery = jqProxy; } </script> <script> jQuery.extend(true, XF.config, { // xlink: { platformId: 0 }, userId: 0, enablePush: true, pushAppServerKey: 'BHawDCc5f/kxves/mySH6irZC+n8kQpwVp6mw8IItmRcI/R6qHIwbanIkiZvdq/o+uUlVEU0XDw0ctRSlmUne1w=', url: { fullBase: 'https://www.physicsforums.com/', basePath: '/', css: '/css.php?css=__SENTINEL__&s=12&l=1&d=1740257292', keepAlive: '/login/keep-alive' }, cookie: { path: '/', domain: '', prefix: 'xf_', secure: true, consentMode: 'disabled', consented: ["optional","_third_party"] }, cacheKey: '2760c734f7bbf2931d9aeae40ac5e6a1', csrf: '1740275182,f09366488176b7f82cfbccf1d7ecada0', js: {}, css: {"public:bb_code.less":true,"public:message.less":true,"public:pf_first_post_rss.css":true,"public:physicsforums_badges.less":true,"public:share_controls.less":true,"public:structured_list.less":true,"public:thxpress_xf.less":true,"public:xb.less":true,"public:extra.less":true}, time: { now: 1740275182, today: 1740204000, todayDow: 6, tomorrow: 1740290400, yesterday: 1740117600, week: 1739685600 }, borderSizeFeature: '3px', fontAwesomeWeight: 'l', enableRtnProtect: true, enableFormSubmitSticky: true, uploadMaxFilesize: 62914560, allowedVideoExtensions: ["m4v","mov","mp4","mp4v","mpeg","mpg","ogv","webm"], allowedAudioExtensions: ["mp3","opus","ogg","wav"], shortcodeToEmoji: true, visitorCounts: { conversations_unread: '0', alerts_unviewed: '0', total_unread: '0', title_count: true, icon_indicator: true }, jsState: {}, publicMetadataLogoUrl: 'https://www.physicsforums.com/styles/physicsforums/images/physics-forums-logo-og.png', publicPushBadgeUrl: 'https://www.physicsforums.com/styles/default/xenforo/bell.png' }); jQuery.extend(XF.phrases, { // "svStandardLib_time.day": "{count} day", "svStandardLib_time.days": "{count} days", "svStandardLib_time.hour": "{count} hour", "svStandardLib_time.hours": "{count} hours", "svStandardLib_time.minute": "{count} minutes", "svStandardLib_time.minutes": "{count} minutes", "svStandardLib_time.month": "{count} month", "svStandardLib_time.months": "{count} months", "svStandardLib_time.second": "{count} second", "svStandardLib_time.seconds": "{count} seconds", "svStandardLib_time.week": "time.week", "svStandardLib_time.weeks": "{count} weeks", "svStandardLib_time.year": "{count} year", "svStandardLib_time.years": "{count} years", CMTV_Code_copied: "Code copied to clipboard.", date_x_at_time_y: "{date} at {time}", day_x_at_time_y: "{day}, {time}", yesterday_at_x: "Yesterday, {time}", x_minutes_ago: "{minutes} minutes ago", one_minute_ago: "1 minute ago", a_moment_ago: "A moment ago", today_at_x: "Today, {time}", in_a_moment: "In a moment", in_a_minute: "In a minute", in_x_minutes: "In {minutes} minutes", later_today_at_x: "Later today at {time}", tomorrow_at_x: "Tomorrow at {time}", day0: "Sunday", day1: "Monday", day2: "Tuesday", day3: "Wednesday", day4: "Thursday", day5: "Friday", day6: "Saturday", dayShort0: "Sun", dayShort1: "Mon", dayShort2: "Tue", dayShort3: "Wed", dayShort4: "Thu", dayShort5: "Fri", dayShort6: "Sat", month0: "January", month1: "February", month2: "March", month3: "April", month4: "May", month5: "June", month6: "July", month7: "August", month8: "September", month9: "October", month10: "November", month11: "December", active_user_changed_reload_page: "The active user has changed. Reload the page for the latest version.", server_did_not_respond_in_time_try_again: "The server did not respond in time. Please try again.", oops_we_ran_into_some_problems: "Oops! We ran into some problems.", oops_we_ran_into_some_problems_more_details_console: "Oops! We ran into some problems. Please try again later. More error details may be in the browser console.", file_too_large_to_upload: "The file is too large to be uploaded.", uploaded_file_is_too_large_for_server_to_process: "The uploaded file is too large for the server to process.", files_being_uploaded_are_you_sure: "Files are still being uploaded. Are you sure you want to submit this form?", attach: "Attach files", rich_text_box: "Rich text box", close: "Close", link_copied_to_clipboard: "Link copied to clipboard.", text_copied_to_clipboard: "Text copied to clipboard.", loading: "Loading…", you_have_exceeded_maximum_number_of_selectable_items: "You have exceeded the maximum number of selectable items.", processing: "Processing", 'processing...': "Processing…", showing_x_of_y_items: "Showing {count} of {total} items", showing_all_items: "Showing all items", no_items_to_display: "No items to display", number_button_up: "Increase", number_button_down: "Decrease", push_enable_notification_title: "Push notifications enabled successfully at Physics Forums: Science Discussion, Homework Help, Articles", push_enable_notification_body: "Thank you for enabling push notifications!", pull_down_to_refresh: "Pull down to refresh", release_to_refresh: "Release to refresh", refreshing: "Refreshing…" }); </script> <form style="display:none" hidden="hidden"> <input type="text" name="_xfClientLoadTime" value="" id="_xfClientLoadTime" title="_xfClientLoadTime" tabindex="-1" /> </form>  <script type="application/ld+json"> { "@context": "https://schema.org", "@type": "WebPage", "url": "https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/", "mainEntity": { "@type": "DiscussionForumPosting", "@id": "https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/", "headline": "Two recent tests of loop quantum gravity theory", "datePublished": "2024-04-03T01:19:55+00:00", "keywords": "Gravity, Loop, Quantum", "url": "https://www.physicsforums.com/threads/two-recent-tests-of-loop-quantum-gravity-theory.1061460/", "articleSection": "Beyond the Standard Models", "author": { "@type": "Person", "@id": "https://www.physicsforums.com/members/kodama.551353/", "name": "kodama", "url": "https://www.physicsforums.com/members/kodama.551353/" }, "interactionStatistic": [ { "@type": "InteractionCounter", "interactionType": "https://schema.org/ViewAction", "userInteractionCount": 3161 }, { "@type": "InteractionCounter", "interactionType": "https://schema.org/CommentAction", "userInteractionCount": 15 }, { "@type": "InteractionCounter", "interactionType": "https://schema.org/LikeAction", "userInteractionCount": 0 } ], "dateModified": "2024-04-03T06:25:20+00:00", "articleBody": "2 recent gains on loop quantum gravity theory\n\n arXiv:2403.18606 (gr-qc)\n[Submitted on 27 Mar 2024]\nTest the Loop Quantum Gravity Theory via the Lensing Effect\nLai Zhao, Meirong Tang, Zhaoyi Xu\n\nRecently, scholars such as Lewandowski, Ma, and Yang have successfully derived a quantum-corrected black hole model in loop quantum gravity (Phys.Rev.Lett.130.101501 (2023)), which is a modification of the Schwarzschild black hole. In this paper, we calculate the strong/weak gravitational lensing effects under the quantum-corrected black hole model, taking the supermassive black holes M87* and SgrA* as the subjects of study to explore the impact of the quantum correction parameter \u03b1 on the positions of images and the Einstein ring. Our calculations show that in the case of strong gravitational lensing, the lensing coefficient a\u00af increases with an increase in the quantum correction parameter, while the deflection angle and the lensing coefficient b\u00af decrease with an increase in the quantum correction parameter. The quantum correction parameter \u03b1 has a significant impact in the context of supermassive black holes. In weak gravitational lensing, the quantum correction parameter \u03b1 plays a suppressive role. Our theoretical analysis suggests that with advancements in future astrophysical observation techniques, it might be possible to test loop quantum gravity theory using the gravitational lensing effect.\n\nSubjects: General Relativity and Quantum Cosmology (gr-qc)\nCite as: arXiv:2403.18606 [gr-qc]\n (or arXiv:2403.18606v1 [gr-qc] for this version)\n\n\nhttps://doi.org/10.48550/arXiv.2403.18606\n\nand\n\n [Submitted on 7 Dec 2023 (v1), last revised 28 Dec 2023 (this version, v2)]\nShadows of Loop Quantum Black Holes: Semi-analytical Simulations of Loop Quantum Gravity Effects on Sagittarius A* and M 87*\nHong-Xuan Jiang, Cheng Liu, Indu K. Dihingia, Yosuke Mizuno, Haiguang Xu, Tao Zhu, Qiang Wu\n\n\nIn this study, we delve into the observational implications of rotating Loop Quantum Black Holes (LQBHs) within an astrophysical framework. We employ semi-analytical General Relativistic Radiative Transfer (GRRT) computations to study the emission from the accretion flow around LQBHs. Our findings indicate that the increase of Loop Quantum Gravity (LQG) effects results in an enlargement of the rings from LQBHs, thereby causing a more circular polarization pattern in the shadow images. We make comparisons with the Event Horizon Telescope (EHT) observations of Sgr\\,A\u2217 and M\\,87\u2217, which enable us to determine an upper limit for the polymetric function P in LQG. The upper limit for Sgr\\,A\u2217 is 0.2, while for M\\,87\u2217 it is 0.07. Both black holes exhibit a preference for a relatively high spin (a\u22730.5 for Sgr\\,A\u2217 and 0.5\u2272a\u22720.7 for M\\,87\u2217). The constraints for Sgr\\,A\u2217 are based on black hole spin and ring diameter, whereas for M\\,87\u2217, the constraints are further tightened by the polarimetric pattern. In essence, our simulations provide observational constraints on the effect of LQG in supermassive black holes (SMBH), providing the most consistent comparison with observation.\nSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE)\nCite as: arXiv:2312.04288 [gr-qc]\n (or arXiv:2312.04288v2 [gr-qc] for this version)\n\n\nhttps://doi.org/10.48550/arXiv.2312.04288\n\nand\n\n arXiv:2305.04336 (gr-qc)\n[Submitted on 7 May 2023 (v1), last revised 30 Oct 2023 (this version, v2)]\nStrong Gravitational Lensing by Loop Quantum Gravity Motivated Rotating Black Holes and EHT Observations\nJitendra Kumar, Shafqat Ul Islam, Sushant G. Ghosh\n We investigate gravitational lensing in the strong deflection regime by loop quantum gravity (LQG)-motivated rotating black hole (LMRBH) metrics with an additional parameter l besides mass M and rotation a. The LMRBH spacetimes are regular everywhere, asymptotically encompassing the Kerr black hole as a particular case and, depending on the parameters, describe black holes with one horizon only (BH-I), black holes with an event horizon and a Cauchy horizon (BH-II), black holes with three horizons (BH-III), or black holes with no horizons (NH) spacetime. It turns out that as the LQG parameter l increases, the unstable photon orbit radius xps, the critical impact parameter ups, the deflection angle \u03b1D(\u03b8) and angular position \u03b8\u221e also increases. Meanwhile, the angular separation s decreases, and relative magnitude rmag increases with increasing l for prograde motion but they show opposite behaviour for the retrograde motion. For Sgr A*, the angular position \u03b8\u221e is \u2208 (16.4, 39.8) \u03bcas, while for M87* \u2208 (12.33, 29.9) \u03bcas. The angular separation s, for SMBHs Sgr A* and M87*, differs significantly, with values ranging \u2208 (0.008-0.376) \u03bcas for Sgr A* and \u2208 (0.006-0.282) \u03bcas for M87*. We estimate the time delay between the first and second relativistic images using twenty supermassive galactic centre black holes as lenses. Our analysis concludes that, within the 1\u03c3 region, a significant portion of the BH-I and BH-II and for a small portion of BH-III parameter space agrees with the EHT results of M87* and Sgr A* whereas NH is completely ruled out. We discover that the EHT results of Sgr A* place more stringent limits on the parameter space of LMRBH black holes than those established by the EHT results of M87*. \n\nComments: 16 Pages, 11 Figures, 3 Tables, Accepted for publication in EPJC\nSubjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics of Galaxies (astro-ph.GA)\nCite as: arXiv:2305.04336 [gr-qc]\n (or arXiv:2305.04336v2 [gr-qc] for this version) \n\nand \n\n arXiv:2302.10482 (gr-qc)\n[Submitted on 21 Feb 2023 (v1), last revised 29 Apr 2023 (this version, v2)]\nObservational tests of quantum extension of Schwarzschild spacetime in loop quantum gravity with stars in the galactic center\nJian-Ming Yan, Cheng Liu, Tao Zhu, Qiang Wu, Anzhong Wang\n \n\n In this paper, we use the publicly available observational data of 17 stellar stars orbiting Sgr A* to test the quantum extension of Schwarzschild spacetime in loop quantum gravity (LQG). For our purpose, we transform the geodesical evolution of a massive particle in the quantum-extended Schwarzschild black hole to the perturbed Kepler problem and calculate the effects of LQG on the pericentre advance of the stellar stars. With these effects, one is able to compare them with the publicly available astrometric and spectroscopic data of stellar stars in the galactic center. We perform Monte Carlo Markov Chain (MCMC) simulations to probe the possible LQG effects on the orbit of S-stars. No significant evidence of the quantum-extended Schwarzschild black hole from LQG is found. Among the posterior analyses of 17 S-stars, the result of S2 gives the strongest bound on the LQG parameter A\u03bb, which places an upper bound at 95\\% confidence level on A\u03bb to be A\u03bb<0.302. \n\nComments: 12 pages, 6 figures\nSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)\nCite as: arXiv:2302.10482 [gr-qc]\n (or arXiv:2302.10482v2 [gr-qc] for this version)\n \nhttps://doi.org/10.48550/arXiv.2302.10482\nJournal reference: Phys. Rev. D 107, 084043 (2023)\nRelated DOI: \nhttps://doi.org/10.1103/PhysRevD.107.084043\n\n\n\n arXiv:2403.17197 (hep-th)\n[Submitted on 25 Mar 2024]\nLoop Quantum Gravity effects on electromagnetic properties of charged leptons\nJo\u00e3o Paulo S. Melo, Mario J. Neves, Jefferson M. A. Paix\u00e3o, Jos\u00e9 A. Helay\u00ebl-Neto\n\n\nThe efforts in this contribution consist in reassessing a modified Dirac equation that incorporates a \u03b30\u03b35-Lorentz-symmetry violating (LSV) term induced as a Loop Quantum Gravity (LQG) effect. Originally, this equation has been applied and considered as a good scenario for describing a number of investigations on the flight time of cosmic photons and neutrinos, which suggests that the speed of light in vacuum, in connection with the geometry that describes a granular space-time, takes an energy-dependent form, e.g., v(E)=1\u00b1E/ELSV, with ELSV\u22486,5\u00d71017 GeV for neutrinos. Once LQG provides a viable way to consistently understand this picture, we pursue an analysis of this effective Dirac equation to inspect some of its properties. These include: the derivation of the modified fermionic propagator, attainment of the Gordon decomposition of the vector current with minimal electromagnetic coupling to obtain information on the form factors, examination of the non-relativistic limit of the equation, evaluation of the spin- and velocity-dependent corrections to the Coulomb potential due to LQG effects, and the modified Hamiltonian in the low-relativistic regime. The study of the form factors may open up paths to set up bounds on the LQG parameters from the precision measurements of electromagnetic attributes of the charged leptons, such as their respective electric and magnetic dipole moments.\n\nComments: 11 pages, 2 figures\nSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Phenomenology (hep-ph)\nCite as: arXiv:2403.17197 [hep-th]\n (or arXiv:2403.17197v1 [hep-th] for this version))\n\n\nhttps://doi.org/10.48550/arXiv.2403.17197\n\nany comment on test loop quantum gravity theory on electromagnetic properties of charged leptons and via the Lensing Effect\n\nare those predictions the strong/weak gravitational lensing effects under the quantum-corrected black hole model, taking the supermassive black holes M87* and SgrA* as the subjects of study on unique to loop quantum gravity theory\nor\ncould string theory, SUGRA, semiclassical gravity also make predictions strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA* via the Lensing Effect\n\nwhat if observations of strong gravitational lensing, the lensing of supermassive black holes M87* and SgrA* confirm loop quantum gravity theory\n\nattributes of the charged leptons, such as their respective electric and magnetic dipole moments is something useful for connecting to experiment by electron EDM\n\nif loop quantum gravity theory on electromagnetic properties of charged leptons and via the Lensing Effect confirm by future experiment should Nobel Prize be awarded and loop quantum gravity theorywins over string theory ?" }, "publisher": { "@type": "Organization", "name": "Physics Forums: Science Discussion, Homework Help, Articles", "alternateName": "Physics Forums", "description": "Join Physics Forums, where students, scientists, and enthusiasts come together to explore and discuss the current understanding and practice of various scientific fields.", "url": "https://www.physicsforums.com", "logo": "https://www.physicsforums.com/styles/physicsforums/images/physics-forums-logo-og.png" } } </script> <script type="text/javascript" src="https://www.physicsforums.com/copyright.js" defer></script> <script> function parseNewPost(postid) { var newpost = document.getElementById("js-post-" + postid), npa = [newpost]; MathJax.typeset(npa); } function parsePreview() { var preview = document.getElementsByClassName("xfPreview"); MathJax.typeset(preview); } function parseNewConversationPost(postid) { var newpost = document.getElementsByClassName("convMessage-" + postid); MathJax.typeset(newpost); } function parseNewProfilePost(postid) { var newpost = document.getElementById("js-profilePost-" + postid), npa = [newpost]; MathJax.typeset(npa); } function parseTooltip() { MathJax.typeset(); } </script> </body> </html>

CINXE.COM

Two recent tests of loop quantum gravity theory