Stability of gravitating charged-scalar solitons in a cavity

TL;DR

This paper introduces new regular gravitating charged-scalar soliton solutions within a cavity, analyzing their stability under linear perturbations, and finds that stability depends on the cavity size.

Contribution

It provides the first detailed stability analysis of Einstein-charged scalar solitons in a cavity with a reflecting boundary.

Findings

Stable solitons for sufficiently large cavity radius

Unstable solitons for small cavity radius

Numerical evidence supporting stability criteria

Abstract

We present new regular solutions of Einstein-charged scalar field theory in a cavity. The system is enclosed inside a reflecting mirror-like boundary, on which the scalar field vanishes. The mirror is placed at the zero of the scalar field closest to the origin, and inside this boundary our solutions are regular. We study the stability of these solitons under linear, spherically symmetric perturbations of the metric, scalar and electromagnetic fields. If the radius of the mirror is sufficiently large, we present numerical evidence for the stability of the solitons. For small mirror radius, some of the solitons are unstable. We discuss the physical interpretation of this instability.