Gravitational lensing by black holes in the 4D Einstein-Gauss-Bonnet gravity

By Shafqat Ul Islam, Rahul Kumar, Sushant G. Ghosh. Journal of Cosmology and Astroparticle Physics, 2020

196 citations recorded by the source corpus.

Recently, a non-trivial 4D Einstein-Gauss-Bonnet (EGB) theory of gravity, by rescaling the GB coupling parameter as α/(D−4), was formulated in [1], which bypasses Lovelock's theorem and avoids Ostrogradsky instability. The theory admits a static spherically symmetric black hole, unlike 5D EGB or general relativity counterpart, which can have both Cauchy and event horizons. We generalize previous work, on gravitational lensing by a Schwarzschild black hole, in the strong and weak deflection limits to the 4D EGB black holes to calculate the deflection coefficients ā and b̄, while former increases and later decrease with increasing α. We also find that the deflection angle αD, angular position θ∞ and um decreases, but angular separation s increases with α. The effect of the GB coupling parameter α on positions and magnification of the source relativistic images is discussed in the context of SgrA* and M87* black holes. A brief description of the weak gravitational lensing using the Gauss-Bonnet theorem is presented.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/165b2c0de3b4eba44fca9ae2b7ef0ebee2160042

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

  1. Hongbao Zhang
  2. Hai-Qing Zhang
  3. Xiao-Xiong Zeng

In Nuclear and High Energy Physics

  1. Hongbao Zhang
  2. Hai-Qing Zhang
  3. Xiao-Xiong Zeng

Citations in the corpus