Excited oscillons: cascading levels and higher multipoles

TL;DR

This paper explores excited oscillons with higher energy levels and multipoles, revealing their long lifetimes, cascade decay behavior, and shorter lifespan for higher multipole configurations through simulations and perturbative analysis.

Contribution

It introduces a detailed study of excited oscillons with multiple energy levels and multipoles, combining nonlinear simulations and perturbative methods.

Findings

Long-lived spherical oscillons with multiple nodes

Cascade decay from higher to lower energy levels

Higher multipole oscillons have shorter lifespans

Abstract

Two types of excited oscillons are investigated. We first focus on spherical symmetry and find that there are a tower of spherical oscillons with higher energies. Despite having multiple approximate "nodes" in their energy density profiles, these oscillons are long-lived. We find that during the lifetime of a highly excited oscillon it will cascade down all the lower energy levels before its disintegration. We also point out the existence of excited oscillons with higher approximate multipoles, which generally have shorter lifespans than the spherical ones. Apart from performing nonlinear simulations with absorbing boundary conditions, we also apply a perturbative method to analyze some features of these excited oscillons.