Vacuum defects without a vacuum

TL;DR

This paper explores vacuum defects in models with no potential minima, highlighting their unique properties and potential roles in cosmic structure formation and mini-black hole production.

Contribution

It introduces the concept of vacuum defects arising in models without minima in the scalar potential, differing from traditional topological defects.

Findings

Vacuum defects can act as seeds for cosmic structure formation.

They may generate a significant density of mini-black holes.

Their properties differ markedly from standard strings and monopoles.

Abstract

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 $|\phi|$. The properties of such vacuumless defects are quite different from those of the ``usual'' strings and monopoles. In some models such defects can serve as seeds for structure formation, or produce an appreciable density of mini-black holes.