Black holes and quasiblack holes in Einstein-Maxwell theory

TL;DR

This paper explores how sequences of solutions in Einstein-Maxwell theory can approach black hole states, revealing both external and internal geometric changes, including special cases like extremal Reissner-Nordstrom and Kerr black holes.

Contribution

It demonstrates the continuous transition of matter configurations into black holes within Einstein-Maxwell theory, highlighting the internal and external geometric properties at the limit.

Findings

Sequences of solutions can reach black hole limits with distinct external metrics.

Internal spacetime remains regular but non-asymptotically flat at the limit.

Special cases include extremal Reissner-Nordstrom and Kerr black holes.

Abstract

Continuous sequences of asymptotically flat solutions to the Einstein-Maxwell equations describing regular equilibrium configurations of ordinary matter can reach a black hole limit. For a distant observer, the spacetime becomes more and more indistinguishable from the metric of an extreme Kerr-Newman black hole outside the horizon when approaching the limit. From an internal perspective, a still regular but non-asymptotically flat spacetime with the extreme Kerr-Newman near-horizon geometry at spatial infinity forms at the limit. Interesting special cases are sequences of Papapetrou-Majumdar distributions of electrically counterpoised dust leading to extreme Reissner-Nordstrom black holes and sequences of rotating uncharged fluid bodies leading to extreme Kerr black holes.