Formation and decay of Einstein-Yang-Mills black holes

TL;DR

This paper investigates the formation, stability, and critical phenomena of Einstein-Yang-Mills black holes using numerical simulations, revealing new attractors and analyzing their decay and perturbations.

Contribution

It introduces a comprehensive numerical study of Einstein-Yang-Mills black holes, including their perturbations, nonlinear evolution, and critical collapse phenomena, extending previous work with new initial data.

Findings

Reissner-Nordstrom black holes serve as new approximate attractors.

Colored black holes can be critical solutions in gravitational collapse.

The lifetime of unstable black holes aligns with an information-theoretic bound.

Abstract

We study various aspects of black holes and gravitational collapse in Einstein-Yang-Mills theory under the assumption of spherical symmetry. Numerical evolution on hyperboloidal surfaces extending to future null infinity is used. We begin by constructing colored and Reissner-Nordstrom black holes on surfaces of constant mean curvature and analyze their perturbations. These linearly perturbed black holes are then evolved into the nonlinear regime and the masses of the final Schwarzschild black holes are computed as a function of the initial horizon radius. We compare with an information-theoretic bound on the lifetime of unstable hairy black holes derived by Hod. Finally we study critical phenomena in gravitational collapse at the threshold between different Yang-Mills vacuum states of the final Schwarzschild black holes, where the n=1 colored black hole forms the critical solution. The work of Choptuik et al. (1999) is extended by using a family of initial data that includes another region in parameter space where the colored black hole with the opposite sign of the Yang-Mills potential forms the critical solution. We investigate the boundary between the two regions and discover that the Reissner-Nordstrom solution appears as a new approximate codimension-two attractor.