Dynamical formation of axionic hair around charged black hole

TL;DR

This study uses nonlinear numerical simulations to explore how axionic potentials influence the dynamical formation of scalar hair around charged black holes, revealing effects on black hole mass and scalar field behavior.

Contribution

It introduces a detailed numerical analysis of scalarization in Einstein-Maxwell-dilaton theory with axionic potentials, highlighting their impact on black hole properties.

Findings

Axionic potential can increase or decrease the black hole's irreducible mass.

Scalar field value on the horizon decreases with axionic potential.

Coupling strength affects the final scalarized black hole state.

Abstract

In this paper, we present a nonlinear numerical investigation on the dynamical scalarization process of a Reissner-Nordstr\"om black hole, incorporating an axionic scalar potential within the framework of the Einstein-Maxwell-dilaton theory. By scrutinizing the evolution of the irreducible mass of the black hole and the value of scalar field on the apparent horizon across various parameters of the axionic potential, we elucidate the correlations between the final states of scalarized charged black hole and the axionic potential. We observe that the inclusion of the axionic potential can either decrease or increase the irreducible mass of the final scalarized black hole, depending on the strength of the coupling between the dilation and the electric invariant $F_{\mu\nu}F^{\mu\nu}$. Regarding the value of the scalar field on the apparent horizon, we find that it decreases with the inclusion of the axionic potential. Our results contribute to an important understanding of the dynamical scalarization of black holes and the potential configurations of scalar hair with various self-interactions.