Oscillons from $Q$-balls

TL;DR

This paper demonstrates how oscillons in (1+1)-dimensions can be derived from $Q$-balls using Renormalization Group Theory, revealing amplitude modulations due to bound states of $Q$-balls.

Contribution

It introduces a novel approach linking $Q$-balls and oscillons via RG theory, extending perturbative methods to explain oscillon modulations.

Findings

Oscillons can be derived from $Q$-balls using RG theory.

Amplitude modulations are explained by two-$Q$-ball bound states.

Universal complex field theories approximate $Q$-balls with nonzero cubic or quartic terms.

Abstract

Using Renormalization Group Theory we show that oscillons in (1+1)-dimensions can be obtained, at the leading nonlinear order, from $Q$-balls of universal complex field theories. For potentials with a nonzero cubic or quartic term the universal $Q$-ball theory is well approximated by the integrable complex sine-Gordon model. This allows us to generalize the usual perturbative expansion by Fodor et. al. beyond the simplest unmodulated oscillon case. Concretely, we explain the characteristic amplitude modulations of excited oscillons as an effect of formation of a two-$Q$-ball (two-oscillon) bound state.