A new approach and code for spinning black holes in modified gravity

TL;DR

This paper introduces a spectral method code in Julia for computing stationary, axisymmetric black hole solutions in modified gravity theories, demonstrating high accuracy and speed in tests with general relativity and Einstein-Scalar-Gauss-Bonnet gravity.

Contribution

The paper presents a new spectral method and Julia implementation for efficiently computing black hole solutions in modified gravity, adaptable to various theories.

Findings

Code achieves tiny errors (~10^{-13}) in solutions.

Method converges rapidly in seconds.

Validated on general relativity and Einstein-Scalar-Gauss-Bonnet gravity.

Abstract

We discuss and implement a spectral method approach to computing stationary and axisymmetric black hole solutions and their properties in modified theories of gravity. The resulting code is written in the Julia language and is transparent and easily adapted to new settings. We test the code on both general relativity and on Einstein-Scalar-Gauss-Bonnet gravity. It is accurate and fast, converging on a spinning solution in these theories with tiny errors ($\sim \mathcal{O}\left(10^{-13}\right)$ in most cases) in a matter of seconds.