Bondi and Novikov-Thorne accretion in regular black holes and Simpson-Visser spacetimes

TL;DR

This paper compares accretion models around regular black holes and Simpson-Visser spacetimes, highlighting the Bondi model's sensitivity to spacetime geometry and the effects of regularisation parameters.

Contribution

It provides a comparative analysis of accretion models on regular black holes and introduces how parameters like $\, ext{ extbackslash}ell$ and $Q$ influence accretion dynamics.

Findings

Bondi model is more sensitive to spacetime geometry and equation of state.

Increasing $\, ext{ extbackslash}ell$ shifts critical points inward and outward.

Charged Simpson-Visser extension's effects are less significant than $\, ext{ extbackslash}ell$.

Abstract

We compare the Bondi spherical accretion model and the Novikov-Thorne thin disc formalism around regular black holes and Simpson-Visser spacetimes, using several equations of state for the accreting fluids. The Bondi model is significantly more sensitive to spacetime geometry and the equation of state, making it more effective at distinguishing between regular and classical solutions. For the Simpson-Visser solutions, however, increasing the regularisation parameter, $\ell$, shifts critical point positions both inward and outward. However, the charged Simpson-Visser extension, modeled by the charge $Q$, does not produce an effect comparable to that of $\ell$.