K-Oscillons: Oscillons with Non-Canonical Kinetic Terms

TL;DR

This paper introduces the first known oscillons in scalar field theories with non-canonical kinetic terms, deriving conditions for their existence and stability, and analyzing their potential for collapse in higher dimensions.

Contribution

It provides the first explicit analysis of oscillons supported solely by non-canonical kinetic terms, including existence conditions and stability analysis.

Findings

Oscillons can exist without nonlinear potential terms due to non-canonical kinetic effects.

Small-amplitude oscillons are stable in certain dimensions, but unstable for d > 2.

Long-wavelength instabilities can cause radial collapse in higher dimensions.

Abstract

Oscillons are long-lived, localized, oscillatory scalar field configurations. In this work we derive a condition for the existence of small-amplitude oscillons (and provide solutions) in scalar field theories with non-canonical kinetic terms. While oscillons have been studied extensively in the canonical case, this is the first example of oscillons in scalar field theories with non-canonical kinetic terms. In particular, we demonstrate the existence of oscillons supported solely by the non-canonical kinetic terms, without any need for nonlinear terms in the potential. In the small-amplitude limit, we provide an explicit condition for their stability in d+1 dimensions against long-wavelength perturbations. We show that for d > 2, there exists a long-wavelength instability which can lead to radial collapse of small-amplitude oscillons.