Spinning Black Holes in Modified Gravity via Spectral Methods
Phys. Rev. Lett. 136, 021401 – Published 15 January, 2026
DOI: https://doi.org/10.1103/6z43-xdv7
Abstract
Rapidly rotating black-hole spacetimes outside general relativity are key to many tests of Einstein’s theory. We here develop an efficient spectral method to represent such spacetimes analytically, in closed-form, and to high accuracy, in a large class of effective-field-theory extensions of general relativity. We exemplify this method by constructing, for the first time, closed-form and analytic representations of spinning black holes in scalar-Gauss-Bonnet, dynamical Chern-Simons, and axidilaton gravity to an accuracy better than for all dimensionless spins below 0.99.