Geodesics and Geodesic Deviation in static Charged Black Holes

TL;DR

This paper investigates null geodesics, circular photon orbits, and gravitational effects in static charged black holes, specifically Reissner-Nordström and stringy charged black holes, highlighting differences from Schwarzschild black holes.

Contribution

It provides a detailed analysis of null geodesics and photon orbits in charged black holes, revealing differences from Schwarzschild solutions and exploring gravitational interactions in stringy charged black holes.

Findings

Photon orbit radii differ between charged and Schwarzschild black holes.

Effective potential properties vary with black hole charge.

Gravitational effects between test particles are influenced by charge type.

Abstract

The radial motion along null geodesics in static charged black hole space-times, in particular, the Reissner-Nordstr\"om and stringy charged black holes are studied. We analyzed the properties of the effective potential. The circular photon orbits in these space-times are investigated. We found that the radius of circular photon orbits in both charged black holes are different and differ from that given in Schwarzschild space-time. We studied the physical effects of the gravitational field between two test particles in stringy charged black hole and compared the results with that given in Schwarzschild and Reissner-Nordstr\"om black holes.