Gravitational lensing and shadows of dilatonic black holes in dilaton-massive gravity
This paper presents optical and astrophysical aspects of charged dilatonic black holes within the framework of dilaton-massive gravity, a promising extension of General Relativity motivated by low-energy string theory. By incorporating a nonminimally coupled scalar dilaton field and massive graviton...
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| Language: | English |
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Elsevier
2025-09-01
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| Series: | Nuclear Physics B |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0550321325002846 |
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| author | Shahid Chaudhary Talha Anwar Farruh Atamurotov Ali M. Mubaraki M.M. Alam |
| author_facet | Shahid Chaudhary Talha Anwar Farruh Atamurotov Ali M. Mubaraki M.M. Alam |
| author_sort | Shahid Chaudhary |
| collection | DOAJ |
| description | This paper presents optical and astrophysical aspects of charged dilatonic black holes within the framework of dilaton-massive gravity, a promising extension of General Relativity motivated by low-energy string theory. By incorporating a nonminimally coupled scalar dilaton field and massive graviton terms into the Einstein-Maxwell action, we study static, spherically symmetric black hole solutions characterized by the parameters c1, c2, and m0, which control the strength of scalar-gravity and massive gravity couplings. We use Gauss-Bonnet theorem to compute the weak deflection angle of light around the black hole. The results reveal that the coupling parameter c1 intensifies light bending, while more negative values of c2 and higher graviton masses m0 suppress it. Extending this analysis to realistic astrophysical settings, we introduce a cold, non-magnetized plasma environment and derive the plasma-corrected deflection angle. The presence of plasma leads to chromatic dispersion, increasing the bending of light at lower frequencies, and amplifying the influence of dilaton-massive gravity on lensing observables. Next, we examine the black hole's shadow by numerically solving for the photon sphere and evaluating the shadow radius. Our findings demonstrate that larger values of c1 and m0 decrease the shadow size due to increased spacetime curvature, whereas increasing c2 expands it by lowering the gravitational potential. These effects are visualized through shadow images in celestial coordinates, clearly illustrating how modified gravity alters the observable structure of black holes. |
| format | Article |
| id | doaj-art-ff8f4a9d1be742b6b511debfe698c8ab |
| institution | Kabale University |
| issn | 0550-3213 |
| language | English |
| publishDate | 2025-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Nuclear Physics B |
| spelling | doaj-art-ff8f4a9d1be742b6b511debfe698c8ab2025-08-20T05:04:22ZengElsevierNuclear Physics B0550-32132025-09-01101811707510.1016/j.nuclphysb.2025.117075Gravitational lensing and shadows of dilatonic black holes in dilaton-massive gravityShahid Chaudhary0Talha Anwar1Farruh Atamurotov2Ali M. Mubaraki3M.M. Alam4Department of Natural Sciences and Humanities, University of Engineering and Technology Lahore, New Campus, Pakistan; Research Center of Astrophysics and Cosmology, Khazar University, Baku, AZ1096, 41 Mehseti Street, AzerbaijanSchool of Science, Walailak University, Nakhon Si Thammarat 80160, Thailand; Research Center for Theoretical Simulation and Applied Research in Bioscience and Sensing, Walailak University, Nakhon Si Thammarat 80160, Thailand; Corresponding author.Kimyo International University in Tashkent, Shota Rustaveli str. 156, Tashkent 100121, Uzbekistan; University of Tashkent for Applied Sciences, Str. Gavhar 1, Tashkent 100149, Uzbekistan; Tashkent State Technical University, 100095 Tashkent, UzbekistanDepartment of Mathematics and Statistics, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi ArabiaDepartment of Basic Medical Sciences, College of Applied Medical Science, King Khalid University, Abha, Saudi ArabiaThis paper presents optical and astrophysical aspects of charged dilatonic black holes within the framework of dilaton-massive gravity, a promising extension of General Relativity motivated by low-energy string theory. By incorporating a nonminimally coupled scalar dilaton field and massive graviton terms into the Einstein-Maxwell action, we study static, spherically symmetric black hole solutions characterized by the parameters c1, c2, and m0, which control the strength of scalar-gravity and massive gravity couplings. We use Gauss-Bonnet theorem to compute the weak deflection angle of light around the black hole. The results reveal that the coupling parameter c1 intensifies light bending, while more negative values of c2 and higher graviton masses m0 suppress it. Extending this analysis to realistic astrophysical settings, we introduce a cold, non-magnetized plasma environment and derive the plasma-corrected deflection angle. The presence of plasma leads to chromatic dispersion, increasing the bending of light at lower frequencies, and amplifying the influence of dilaton-massive gravity on lensing observables. Next, we examine the black hole's shadow by numerically solving for the photon sphere and evaluating the shadow radius. Our findings demonstrate that larger values of c1 and m0 decrease the shadow size due to increased spacetime curvature, whereas increasing c2 expands it by lowering the gravitational potential. These effects are visualized through shadow images in celestial coordinates, clearly illustrating how modified gravity alters the observable structure of black holes.http://www.sciencedirect.com/science/article/pii/S0550321325002846Dilatonic black holesDeflection angleMassive gravityShadow images |
| spellingShingle | Shahid Chaudhary Talha Anwar Farruh Atamurotov Ali M. Mubaraki M.M. Alam Gravitational lensing and shadows of dilatonic black holes in dilaton-massive gravity Nuclear Physics B Dilatonic black holes Deflection angle Massive gravity Shadow images |
| title | Gravitational lensing and shadows of dilatonic black holes in dilaton-massive gravity |
| title_full | Gravitational lensing and shadows of dilatonic black holes in dilaton-massive gravity |
| title_fullStr | Gravitational lensing and shadows of dilatonic black holes in dilaton-massive gravity |
| title_full_unstemmed | Gravitational lensing and shadows of dilatonic black holes in dilaton-massive gravity |
| title_short | Gravitational lensing and shadows of dilatonic black holes in dilaton-massive gravity |
| title_sort | gravitational lensing and shadows of dilatonic black holes in dilaton massive gravity |
| topic | Dilatonic black holes Deflection angle Massive gravity Shadow images |
| url | http://www.sciencedirect.com/science/article/pii/S0550321325002846 |
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