Pure Gauss-Bonnet NUT black hole with and without non-central singularity

TL;DR

This paper introduces a new higher-dimensional pure Gauss-Bonnet NUT black hole solution with various horizon and singularity configurations, expanding understanding of NUT spacetimes in modified gravity theories.

Contribution

It presents the first explicit solution of pure Gauss-Bonnet vacuum equations describing NUT black holes with novel horizon and singularity structures.

Findings

Existence of black holes with both event and cosmological horizons.

Identification of regular spacetimes without horizons or singularities.

Discovery of black holes with event horizons but no central singularity.

Abstract

It is known that NUT solution has many interesting features and pathologies like being non-singular and having closed timelike curves. It turns out that in higher dimensions horizon topology cannot be spherical but it has instead to be product of $2$-spheres so as to retain radial symmetry of spacetime. In this letter we wish to present a new solution of pure Gauss-Bonnet $\Lambda$-vacuum equation describing a black hole with NUT charge. It has three interesting cases: (a) black hole with both event and cosmological horizons with singularity being hidden behind the former, (b) a regular spacetime free of both horizon and singularity, and (c) black hole with event horizon without singularity and cosmological horizon. Singularity here is always non-centric at $r \neq 0$.