Signatures of a Schwarzschild-like Black Hole Immersed in Dark Matter Halo

TL;DR

This paper investigates how a dark matter halo influences the properties and observational signatures of a Schwarzschild-like black hole through perturbation analysis, particle motion, and shadow observations.

Contribution

It introduces a detailed study of a Schwarzschild-like black hole in a Dehnen-type dark matter halo, analyzing perturbations, particle trajectories, and shadow constraints, which is novel in combining these aspects.

Findings

Dark matter halo affects quasinormal modes and shadow size.

Constraints on dark matter halo parameters from shadow observations.

Greybody factors vary with perturbation spin and halo properties.

Abstract

Astrophysical black holes are often surrounded by dark matter, which can influence their dynamics and observational signatures. In this work, we study a Schwarzschild-like black hole immersed in a Dehnen-type $(1,4,2)$ dark matter halo and analyse scalar, electromagnetic, and gravitational perturbations in this spacetime. We compute quasinormal modes (QNMs) using the Wentzel-Kramers-Brillouin (WKB) approximation method with Pad\'e approximants, investigate particle motion and photon trajectories, and use black hole shadow observations to place constraints on the halo parameters. We further examine the greybody factors associated with Hawking radiation for different perturbation spins. This combined analysis aims to understand how dark matter environments may affect black hole oscillations, radiation properties, and the corresponding observational signatures.