English

Gravitational lensing by charged black hole in regularized $4D$ Einstein-Gauss-Bonnet gravity

General Relativity and Quantum Cosmology 2020-12-30 v2

Abstract

Among the higher curvature gravities, the most extensively studied theory is the so-called Einstein-Gauss-Bonnet (EGB) gravity, whose Lagrangian contains Einstein term with the GB combination of quadratic curvature terms, and the GB term yields nontrivial gravitational dynamics in D5 D\geq5. Recently there has been a surge of interest in regularizing, a D4 D \to 4 limit of, the EGB gravity, and the resulting regularized 4D4D EGB gravity valid in 4D4D. We consider gravitational lensing by Charged black holes in the 4D4D EGB gravity theory to calculate the light deflection coefficients in strong-field limits aˉ\bar{a} and bˉ\bar{b}, while the former increases with increasing GB parameter α\alpha and charge qq, later decrease. We also find a decrease in the deflection angle αD\alpha_D, angular position θ\theta_{\infty} decreases more slowly and impact parameter for photon orbits umu_{m} more quickly, but angular separation ss increases more rapidly with α\alpha and charge qq. We compare our results with those for analogous black holes in General Relativity (GR) and also the formalism is applied to discuss the astrophysical consequences in the case of the supermassive black holes Sgr A* and M87*.

Keywords

Cite

@article{arxiv.2004.12970,
  title  = {Gravitational lensing by charged black hole in regularized $4D$ Einstein-Gauss-Bonnet gravity},
  author = {Rahul Kumar and Shafqat Ul Islam and Sushant G. Ghosh},
  journal= {arXiv preprint arXiv:2004.12970},
  year   = {2020}
}

Comments

13 pages, 10 figures, and 1 table. Typos corrected and minor changes made. Version accepted in EPJC

R2 v1 2026-06-23T15:07:47.809Z