Accretion Disk Luminosity and Topological Characteristics for a Schwarzschild Black Hole Surrounded by a Hernquist Dark Matter Halo

TL;DR

This paper investigates how a Hernquist dark matter halo affects the properties, accretion disk luminosity, stability, and topology of a Schwarzschild black hole, providing insights into dark matter's influence on black hole signatures.

Contribution

It introduces a comprehensive analysis of the effects of a Hernquist dark matter halo on Schwarzschild black holes, including accretion disk characteristics and topological properties, which is novel in this context.

Findings

Dark matter significantly alters accretion disk luminosity and temperature.

Dark matter influences the stability and quasi-normal modes of the black hole.

Topological properties of black holes are affected by dark matter presence.

Abstract

In this work, we study some characteristics and gravitational signatures of the Schwarzschild black hole immersed in a Hernquist dark matter halo (SBH-HDM). We determine the black hole's remnant radius and mass, which provide useful residual information at the end of its evaporation. We then explore the luminosity of the accretion disk from the SBH-HDM model. In this way, we determine the key orbital parameters of the test particles within the accretion disk, such as angular velocity, angular momentum, energy, and the radius of the innermost stable circular orbit, based on the dark matter model parameters. We also numerically estimate the accretion disk's efficiency in converting matter into radiation. We also demonstrate that dark matter, which significantly alters the geometry surrounding a Schwarzschild black hole, influences the accretion disk's radiative flux, temperature, differential luminosity, and spectral luminosity. The stability of a black hole spacetime is determined in the eikonal regime. The Lyapunov exponent is also analyzed to quantify the stability of the particle regime and to demonstrate the infall into or escape from the black hole to infinity, as well as the quasi-normal modes. Finally, some properties of black holes are studied from a topological perspective.