Observational Signatures of Exact Black Hole Solutions in a Dark Matter Halo

TL;DR

This paper derives exact solutions for black holes within dark matter halos and analyzes their geometric and observational signatures, comparing predictions with astrophysical data to understand black hole-dark matter interactions.

Contribution

It introduces new exact solutions for black holes in dark matter halos and assesses their observational signatures using real astrophysical data and Bayesian inference.

Findings

Constraints on dark matter halo parameters from observational data

Influence of dark matter halos on black hole spacetime geometry

Potential signatures of dark matter in black hole observations

Abstract

In this work, we derive novel exact solutions describing Schwarzschild-like black holes (BHs) embedded in a Dehnen-type dark matter (DM) halo density profile and investigate their geometric, dynamical, and observational signatures arising from such geometries. We begin by analyzing the horizon structure and spacetime curvature invariants, as well as examining the energy conditions associated with the DM halo. Subsequently, we study the influence of the DM halo on both timelike and null geodesics in the resulting geometry. Finally, we obtain observational constraints on the DM halo parameters by comparing the model predictions with weak-field data from Mercury and the S2 star orbit, as well as strong-field observations from the Event Horizon Telescope (EHT), GRAVITY, and combined (EHT+GRAVITY) datasets for M87* and Sgr A*, employing Bayesian inference and Markov Chain Monte Carlo (MCMC) methods to determine the best-fit values and corresponding upper limits of the model parameters. Our analysis provides valuable insight into probing the potential influence of DM halo environments on spacetime geometry and observable properties of astrophysical BHs, offering an alternative perspective on BH-DM interactions.