Polynomial approximation of the Lense-Thirring rigid precession frequency

TL;DR

This paper introduces a polynomial approximation method for the Lense-Thirring precession frequency, enabling efficient predictions of black hole accretion disc oscillations with significantly reduced computational time.

Contribution

A novel polynomial approximation for the Lense-Thirring precession frequency that improves computational efficiency and accuracy in modeling black hole accretion disc oscillations.

Findings

Approximation reduces computation time by a factor of ~70.

Accurate frequency predictions for precessing thick accretion discs.

Applicability regions and accuracy of the approximation are discussed.

Abstract

We propose a polynomial approximation of the global Lense-Thirring rigid precession frequency to study low frequency quasi-periodic oscillations around spinning black holes. This high-performing approximation allows to determine the expected frequencies of a precessing thick accretion disc with fixed inner radius and variable outer radius around a black hole with given mass and spin. We discuss the accuracy and the applicability regions of our polynomial approximation, showing that the computational times are reduced by a factor of $\approx70$ in the range of minutes.