Strong gravitational lensing across dilaton anti-de Sitter black hole

TL;DR

This paper studies the strong gravitational lensing effects near dilaton black holes in anti-de Sitter space, analyzing how the photon sphere, deflection angle, and image properties depend on dilaton coupling and cosmological constant.

Contribution

It provides a detailed analysis of gravitational lensing signatures specific to dilaton anti-de Sitter black holes, highlighting how key parameters influence observable effects.

Findings

Photon sphere radius varies with dilaton coupling and cosmological constant.

Deflection angle depends on black hole parameters.

Distinct image flux ratios can serve as signatures of such black holes.

Abstract

In this work we investigate gravitational lensing effect in strong field region around a dilaton black holes in an anti de Sitter (ADS) space. We also analyse the dependence of the radius of the photon sphere and deflection angle on dilaton coupling and cosmological constant in this black hole space time. Finally the values of minimum impact parameter, the separation between the first and the other images as well as the ratio between the flux of the first image and the flux coming from all the other images are determined to characterize some possible distinct signatures of such black holes.