Geodesic motions in extraordinary string geometry

TL;DR

This paper analyzes the geodesic behavior in an extraordinary string solution in five dimensions, revealing unique properties like stable orbits and the inability of particles to reach horizons or singularities, with implications for different geometries.

Contribution

It provides a detailed analysis of geodesic motions in a novel five-dimensional string geometry, highlighting features distinct from static solutions and exploring orbit precession.

Findings

Particles cannot reach the horizon or singularity via geodesics.

Existence of stable null circular orbits.

Distinct precession angles for different geometries.

Abstract

The geodesic properties of the extraordinary vacuum string solution in (4+1) dimensions are analyzed by using Hamilton-Jacobi method. The geodesic motions show distinct properties from those of the static one. Especially, any freely falling particle can not arrive at the horizon or singularity. There exist stable null circular orbits and bouncing timelike and null geodesics. To get into the horizon {or singularity}, a particle need to follow a non-geodesic trajectory. We also analyze the orbit precession to show that the precession angle has distinct features for each geometry such as naked singularity, black string, and wormhole.