Spontaneous scalarization of self-gravitating magnetic fields

TL;DR

This paper investigates how a real massive scalar field spontaneously condenses in a static, cylindrically symmetric magnetic universe with electromagnetic fields, revealing conditions for scalarization depending on coupling parameters.

Contribution

It demonstrates the spontaneous scalarization of self-gravitating magnetic fields with non-minimal coupling, showing existence conditions and node structures of scalar field solutions.

Findings

Scalar field condenses on Melvin magnetic universe with non-minimal coupling.

Solutions exist within finite coupling intervals, with multiple node solutions.

Existence intervals are mutually exclusive for different node numbers in one case.

Abstract

In this paper, we study the spontaneous scalarization of an extended, self-gravitating system which is static, cylindrically symmetric and possesses electromagnetic fields. We demonstrate that a real massive scalar field condenses on this Melvin magnetic universe solution when introducing a non-minimal coupling between the scalar field and (a) the magnetic field and (b) the curvature of the space-time, respectively. We find that in both cases, the solutions exist on a finite interval of the coupling constant and that solutions with a number of nodes $k$ in the scalar field exist. For case (a) we observe that the intervals of existence are mutually exclusive for different $k$.