Critical solutions of scalarized black holes

TL;DR

This paper investigates charged black holes with scalar hair in Einstein-Maxwell-scalar models, revealing a critical behavior where the spacetime splits at a specific charge, extending understanding of hairy black hole solutions.

Contribution

It identifies and analyzes a critical phenomenon in scalarized charged black holes, showing a spacetime split at a critical charge, a pattern previously seen in non-Abelian monopoles.

Findings

Existence of scalarized black holes beyond Reissner-Nordström solutions

Discovery of a critical charge where spacetime bifurcates

Inner spacetime with scalar hair and outer extremal Reissner-Nordström region

Abstract

We consider charged black holes with scalar hair obtained in a class of Einstein-Maxwell-scalar models, where the scalar field is coupled to the Maxwell invariant with a quartic coupling function. Besides the Reissner-Nordstr\"om black holes, these models allow for black holes with scalar hair. Scrutinizing the domain of existence of these hairy black holes, we observe a critical behavior: A limiting configuration is encountered at a critical value of the charge, where spacetime splits into two parts: an inner spacetime with a finite scalar field and an outer extremal Reissner-Nordstr\"om spacetime. Such a pattern was first observed in the context of gravitating non-Abelian magnetic monopoles and their hairy black holes.