Cloud of strings for radiating black holes in Lovelock gravity

TL;DR

This paper derives exact radiating black hole solutions in third order Lovelock gravity with a string cloud background, analyzing how these clouds and higher curvature terms influence horizon structure and singularities.

Contribution

It introduces new spherically symmetric null dust solutions in third order Lovelock gravity with string clouds, extending known models and exploring their horizon and singularity properties.

Findings

String clouds significantly alter horizon structures.

Coupling constants can lead to naked singularities.

Known solutions are recovered in specific limits.

Abstract

We present exact spherically symmetric null dust solutions in the third order Lovelock gravity with a string cloud background in arbitrary $N$ dimensions,. This represents radiating black holes and generalizes the well known Vaidya solution to Lovelock gravity with a string cloud in the background. We also discuss the energy conditions and horizon structures, and explicitly bring out the effect of the string clouds on the horizon structure of black hole solutions for the higher dimensional general relativity and Einstein-Gauss-Bonnet theories. It turns out that the presence of the coupling constant of the Gauss-Bonnet terms and/or background string clouds completely changes the structure of the horizon and this may lead to a naked singularity. We recover known spherically symmetric radiating models as well as static black holes in the appropriate limits.