Domain defects in systems of two real scalar fields

TL;DR

This paper explores how the symmetry of the Lagrangian influences the existence and structure of defects in coupled scalar field systems, including topological, non-topological, and nested defects, with stability and thermal effects analyzed.

Contribution

It provides a detailed analysis of defect solutions in coupled scalar fields, highlighting the impact of symmetry and space topology on their existence, structure, and stability.

Findings

Existence of topological BPS and non-BPS solutions with internal structure in non-compact space.

Identification of nontopological sphalerons in compact space that can nest inside topological defects.

Analysis of classical stability and thermal effects on defect solutions.

Abstract

In this work we investigate the role of the symmetry of the Lagrangian on the existence of defects in systems of coupled scalar fields. We focus attention mainly on solutions where defects may nest defects. When space is non-compact we find topological BPS and non-BPS solutions that present internal structure. When space is compact the solutions are nontopological sphalerons, which may be nested inside the topological defects. We address the question of classical stability of these topological and nontopological solutions and investigate how the thermal corrections may modify the classical scenario.