Accretion onto a Charged Black Hole in Consistent 4D Einstein-Gauss-Bonnet Gravity

TL;DR

This paper investigates accretion processes around a charged 4D Einstein-Gauss-Bonnet black hole, analyzing particle orbits, fluid dynamics, and accretion disk properties to understand how the EGB parameter and charge influence accretion behavior.

Contribution

It provides analytical formulas and detailed analysis of accretion dynamics in 4D EGB gravity, highlighting the effects of charge and EGB parameter on accretion properties.

Findings

EGB parameter and charge decrease ISCO radius.

Increasing EGB parameter and charge reduce energy flux.

Higher EGB and charge lower energy density and infall velocity.

Abstract

In astrophysics, accretion is the process by which a massive object acquires matter. The infall leads to the extraction of gravitational energy. Accretion onto dark compact objects such as black holes, neutron stars, and white dwarfs is a crucial process in astrophysics as it turns gravitational energy into radiation. The accretion process is an effective technique to investigate the properties of other theories of gravity by examining the behavior of their solutions with compact objects. In this paper, we investigate the behavior of test particles around a charged four dimensional Einstein Gauss Bonnet black hole in order to understand their innermost stable circular orbit (ISCO) and energy flux, differential luminosity, and temperature of the accretion disk. Then, we examine particle oscillations around a central object via applying restoring forces to treat perturbations. Next, we explore the accretion of perfect fluid onto a charged 4D EGB black hole. We develop analytical formulas for four-velocity and proper energy density of the accreting fluid. The EGB parameter and the charge affect properties of the test particles by decreasing their ISCO radius and also decreasing their energy flux. Increasing the EGB parameter and the charge, near the central source reduces both the energy density and the radial component of the infalling fluid's four-velocity.