Geometric Properties and QPOs of Reissner-Nordstrom-AdS Black Hole with a Cloud of Strings Surrounded by Quintessence in Rastall Gravity

Geometric Properties and QPOs of Reissner-Nordstrom-AdS Black Hole with a Cloud of Strings Surrounded by Quintessence in Rastall Gravity | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Geometric Properties and QPOs of Reissner-Nordstrom-AdS Black Hole with a Cloud of Strings Surrounded by Quintessence in Rastall Gravity Faizuddin Ahmed This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7947118/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract In this work, we performed a comprehensive theoretical investigation of the optical and dynamical properties of static, charged anti-de Sitter (AdS) black holes surrounded by a cloud of strings and a quintessence-like fluid, within the framework of Rastall gravity. We derive the effective potential for null geodesics and analyze key optical features such as the effective radial force experienced by photons, photon trajectories, circular photon orbits (photon spheres), and the resulting BH shadows. Furthermore, we explored the topological structure of the photon ring (PR), examining how both geometric and physical parameters influence these features of photon sphere. In addition, we studied the dynamics of neutral test particles using the Hamilton–Jacobi formalism, with particular focus on the innermost stable circular orbit (ISCO). Using the effective potential governing massive particle motion, we investigated quasi-periodic oscillations (QPOs) and computed the fundamental oscillation frequencies. Our results demonstrate how the presence of a string cloud, quintessence-like fluid, and deviations from general relativity significantly affect both the optical and dynamical properties of the BH spacetime. Modified gravity theories Field Equations black holes Geodesic motion quintessence-like fluid quasi periodic oscillations Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7947118","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":535650878,"identity":"59275428-b808-4da9-bf99-daf6fce9d0ad","order_by":0,"name":"Faizuddin Ahmed","email":"data:image/png;base64,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","orcid":"","institution":"The Assam Royal Global University","correspondingAuthor":true,"prefix":"","firstName":"Faizuddin","middleName":"","lastName":"Ahmed","suffix":""}],"badges":[],"createdAt":"2025-10-27 10:48:48","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7947118/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7947118/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":94574794,"identity":"e7ecbc93-e485-4f1c-a11b-7375359b7b7a","added_by":"auto","created_at":"2025-10-28 18:09:04","extension":"json","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":3041,"visible":true,"origin":"","legend":"","description":"","filename":"569fc8d800414a1cb65a259822dfaf45.json","url":"https://assets-eu.researchsquare.com/files/rs-7947118/v1/83bf3f258dcedacf501728e9.json"},{"id":94594859,"identity":"bd156da5-1e43-426b-a686-63187cb75781","added_by":"auto","created_at":"2025-10-28 18:30:48","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3092953,"visible":true,"origin":"","legend":"","description":"","filename":"ChargedBHRastall.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7947118/v1_covered_34be0a6b-522e-4016-816c-5fc79975f19e.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Geometric Properties and QPOs of Reissner-Nordstrom-AdS Black Hole with a Cloud of Strings Surrounded by Quintessence in Rastall Gravity","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Modified gravity theories, Field Equations, black holes, Geodesic motion, quintessence-like fluid, quasi periodic oscillations","lastPublishedDoi":"10.21203/rs.3.rs-7947118/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7947118/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"In this work, we performed a comprehensive theoretical investigation of the optical and dynamical properties of static, charged anti-de Sitter (AdS) black holes surrounded by a cloud of strings and a quintessence-like fluid, within the framework of Rastall gravity. 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