Thin accretion disks onto brane world black holes

TL;DR

This paper investigates the emission properties of accretion disks around brane world black holes, aiming to identify observational signatures that could distinguish them from standard black holes in general relativity.

Contribution

It provides new calculations of energy flux, emission spectrum, and accretion efficiency for various brane world black holes, comparing them with general relativistic models.

Findings

Distinct electromagnetic signatures identified for brane world black holes

Potential observational tests for extra-dimensional theories proposed

Differences in accretion efficiency compared to standard black holes

Abstract

The braneworld description of our universe entails a large extra dimension and a fundamental scale of gravity that might be lower by several orders of magnitude as compared to the Planck scale. An interesting consequence of the braneworld scenario is in the nature of the vacuum solutions of the brane gravitational field equations, with properties quite distinct as compared to the standard black hole solutions of general relativity. One possibility of observationally discriminating between different types of black holes is the study of the emission properties of the accretion disks. In the present paper we obtain the energy flux, the emission spectrum and accretion efficiency from the accretion disks around several classes of static and rotating brane world black holes, and we compare them to the general relativistic case. Particular signatures can appear in the electromagnetic spectrum, thus leading to the possibility of directly testing extra-dimensional physical models by using astrophysical observations of the emission spectra from accretion disks.