Gravitational field of vacuumless defects

TL;DR

This paper investigates the gravitational effects of vacuumless topological defects, revealing unique spacetime structures and gravitational behaviors for global and gauge monopoles and strings.

Contribution

It provides the first detailed analysis of gravitational fields generated by vacuumless defects in both global and gauge symmetry breaking scenarios.

Findings

Global monopoles have strongly repulsive gravity and de Sitter-like horizons.

Gauge monopoles resemble magnetically charged black holes.

Global strings exhibit repulsive gravity, while gauge strings show mixed attractive and repulsive behavior.

Abstract

It has been recently shown that topological defects can arise in symmetry breaking models where the scalar field potential $V(\phi)$ has no minima and is a monotonically decreasing function of $|\phi|$. Here we study the gravitational fields produced by such vacuumless defects in the cases of both global and gauge symmetry breaking. We find that a global monopole has a strongly repulsive gravitational field, and its spacetime has an event horizon similar to that in de Sitter space. A gauge monopole spacetime is essentially that of a magnetically charged black hole. The gravitational field of a global string is repulsive and that of a gauge string is attractive at small distances and repulsive at large distances. Both gauge and global string spacetimes have singularities at a finite distance from the string core.