Critical Phenomena Inside Global Monopoles

TL;DR

This paper investigates critical phenomena in the gravitational collapse of triplet scalar fields, discovering a new discretely self-similar solution with a different echoing period, expanding understanding of monopole collapse dynamics.

Contribution

It identifies a novel DSS solution with a different echoing period in the collapse of triplet scalar fields, including within global monopoles, extending previous critical collapse results.

Findings

New DSS solution with period Δ=0.46 found

Original DSS solution with period Δ=3.44 confirmed in certain models

Hedgehog ansatz influences the critical solution structure

Abstract

The gravitational collapse of a triplet scalar field is examined assuming a hedgehog ansatz for the scalar field. Whereas the seminal work by Choptuik with a single, strictly spherically symmetric scalar field found a discretely self-similar (DSS) solution at criticality with echoing period $\Delta=3.44$, here a new DSS solution is found with period $\Delta=0.46$. This new critical solution is also observed in the presence of a symmetry breaking potential as well as within a global monopole. The triplet scalar field model contains Choptuik's original model in a certain region of parameter space, and hence his original DSS solution is also a solution. However, the choice of a hedgehog ansatz appears to exclude the original DSS.