Null Geodesics of Black Holes in String Theory

Abstract

In this talk, we presented the null geodesics of the static charged black hole in heterotic string theory. The talk is based on a paper published in Physical Review D (Fernando, Phys. Rev. D 85:02403, 2012). In this paper, a detailed analysis of the geodesics are done in the Einstein frame as well as in the string frame. In the Einstein frame, the geodesics are solved exactly in terms of the Jacobi-elliptic integrals for all possible energy levels and angular momentum of the photons. In the string frame, the geodesics are presented for the circular orbits. As a physical application of the null geodesics, we have obtained the angle of deflection for the photons and the quasinormal modes of a massless scalar field in the eikonal limit. © Springer-Verlag Berlin Heidelberg 2014.