Cylindrically Symmetric Black Holes Sourced by Dekel-Zhao Dark Matter

TL;DR

This paper derives analytical solutions for black holes influenced by Dekel-Zhao dark matter, revealing how dark matter parameters affect horizons, singularities, and thermodynamics in various dimensions.

Contribution

It provides new analytical solutions for black strings and black holes sourced by Dekel-Zhao dark matter, highlighting the impact of dark matter on horizon structure and spacetime singularities.

Findings

Event horizon radius depends on the inner slope parameter a.

Dark matter induces curvature singularities absent in vacuum solutions.

Dark matter modifies Hawking temperature and free energy without affecting stability.

Abstract

In this work, we obtain analytical solutions for a $(3+1)$-dimensional black string and a $(2+1)$-dimensional black hole, both sourced by the Dekel-Zhao dark matter (DM) density profile. Our results indicate that the event horizon radius is sensitive to the inner slope parameter $a$; specifically, beyond a critical threshold, the horizon vanishes, leading to the formation of naked singularities. We find that the DM environment induces curvature singularities in the Ricci and Kretschmann scalars, which are absent in the vacuum BTZ case. Furthermore, an analysis of the effective energy-momentum tensor shows that while the null, weak, and strong energy conditions are strictly satisfied, the dominant energy condition is violated in the lower-dimensional scenario due to the high tangential pressure gradient. We also observe that DM modifies the Hawking temperature and free energy without compromising local or global stability. Notably, the DM distribution transforms the originally constant-curvature BTZ spacetime into a singular one, suggesting that a inherent stiffness of the DM profile is a determinant factor in the causal structure of these solutions.