Constrained deflection angle and shadows of rotating black holes in Einstein–Maxwell-scalar theory.

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Bibliographic Details
Title: Constrained deflection angle and shadows of rotating black holes in Einstein–Maxwell-scalar theory.
Authors: Belmahi, Hajar1 (AUTHOR) hajar_belmahi@um5.ac.ma
Source: International Journal of Geometric Methods in Modern Physics. Aug2026, Vol. 23 Issue 9, p1-14. 14p.
Subjects: Deflection (Light), Black holes, Gravitation, Event Horizon Telescope, Hamilton-Jacobi equations, Kerr black holes
Abstract: Motivated by recent Event Horizon Telescope collaboration findings, we investigate constrained optics of rotating black holes in Einstein–Maxwell-scalar gravity theory. Precisely, we mainly study the parameter effects on two relevant optical concepts being the shadow and deflection angle. Using the Hamilton–Jacobi algorithm, we find certain shadow geometries being corroborated by observational data once appropriate constraints on a stringy coupling parameter β are imposed. For such constrained regions of the black hole moduli space, we compute the deflection angle of light rays near to such black holes. Concretely, we show that this optical quantity can be split into two contributions describing the absence and the presence of the coupling parameter β. Then, we discuss and analyse such optical quantity in terms of such β contributions. [ABSTRACT FROM AUTHOR]
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Database: Engineering Source
Description
Abstract:Motivated by recent Event Horizon Telescope collaboration findings, we investigate constrained optics of rotating black holes in Einstein–Maxwell-scalar gravity theory. Precisely, we mainly study the parameter effects on two relevant optical concepts being the shadow and deflection angle. Using the Hamilton–Jacobi algorithm, we find certain shadow geometries being corroborated by observational data once appropriate constraints on a stringy coupling parameter β are imposed. For such constrained regions of the black hole moduli space, we compute the deflection angle of light rays near to such black holes. Concretely, we show that this optical quantity can be split into two contributions describing the absence and the presence of the coupling parameter β. Then, we discuss and analyse such optical quantity in terms of such β contributions. [ABSTRACT FROM AUTHOR]
ISSN:02198878
DOI:10.1142/S0219887825502482