Generalized pseudo-Newtonian potential for studying accretion disk dynamics in off-equatorial planes around rotating black holes: Description of a vector potential

TL;DR

This paper introduces a pseudo-Newtonian vector potential for studying accretion disk dynamics around Kerr black holes, accurately capturing key relativistic features for off-equatorial planes.

Contribution

The authors develop a new vector potential that mimics Kerr spacetime effects, enabling easier analysis of off-equatorial accretion disks with high accuracy.

Findings

Reproduces last stable circular orbit exactly.

Accurately models last bound orbit and energy with minimal error.

Valid for entire Kerr parameter range.

Abstract

We prescribe a pseudo-Newtonian vector potential for studying accretion disks around Kerr black holes. The potential is useful to study the inner properties of disk not confined to the equatorial plane where general relativistic effect is indispensable. Therefore, we incorporate the essential properties of the metric at the inner radii through the pseudo-Newtonian potential derived from the general Kerr spacetime. The potential, reproducing most of the salient features of the general-relativity, is valid for entire regime of Kerr parameter. It reproduces the last stable circular orbit exactly as that in the Kerr geometry. It also reproduces last bound orbit and energy at last stable circular orbit with a maximum error ~7% and ~15% respectively upto an orbital inclination 30 degree.