Oscillons in Higher-Derivative Effective Field Theories

TL;DR

This paper explores how higher derivative terms in effective field theories, like galileons, can support new types of oscillons, which are localized, oscillating solutions with unique differentiability properties.

Contribution

It demonstrates the existence of novel oscillons in higher-derivative theories, specifically in massive galileon models, and analyzes their properties across different spatial dimensions.

Findings

Discovery of new oscillons supported by non-linearities of quartic galileons

Oscillons are of differentiability class C^1, exhibiting unique mathematical properties

Complete analysis of oscillons in 1+1, 2+1, and 3+1 dimensions.

Abstract

We investigate the existence and behavior of oscillons in theories in which higher derivative terms are present in the Lagrangian, such as galileons. Such theories have emerged in a broad range of settings, from higher-dimensional models, to massive gravity, to models for late-time cosmological acceleration. By focusing on the simplest example---massive galileon effective field theories---we demonstrate that higher derivative terms can lead to the existence of completely new oscillons (quasi-breathers). We illustrate our techniques in the artificially simple case of 1 + 1 dimensions, and then present the complete analysis valid in 2 + 1 and 3 + 1 dimensions, exploring precisely how these new solutions are supported entirely by the non-linearities of the quartic galileon. These objects have the novel peculiarity that they are of the differentiability class $C^1$.