Light deflection by squashed Kaluza-Klein black holes in a plasma medium

TL;DR

This paper investigates how light deflection is affected by a squashed Kaluza-Klein black hole in a plasma medium, revealing corrections to general relativity influenced by extra dimensions, black hole charge, and plasma properties.

Contribution

It introduces a model for photon motion in plasma around a five-dimensional black hole, deriving new corrections to light deflection due to extra dimensions and plasma effects.

Findings

Derived correction terms for light deflection angle

Identified influence of extra dimension size and black hole charge

Quantified plasma frequency effects on photon trajectories

Abstract

We study motions of photons in an unmagnetized cold homogeneous plasma medium in the five-dimensional charged static squashed Kaluza-Klein black hole spacetime. In this case, a photon behaves as a massive particle in a four-dimensional spherically symmetric spacetime. We consider the light deflection by the squashed Kaluza-Klein black hole surrounded by the plasma in a weak-field limit. We derive corrections of the deflection angle to general relativity, which are related to the size of the extra dimension, the charge of the black hole and the ratio between the plasma and the photon frequencies.