Spectral walls in antikink-kink scattering in the $\phi^6$ model

TL;DR

The paper demonstrates the existence of spectral walls in antikink-kink collisions within the $^6$ model, caused by delocalized modes that emerge only during collisions, suggesting this is a common phenomenon in non-symmetric soliton interactions.

Contribution

It reveals the presence of spectral walls in the $^6$ model and links their occurrence to delocalized modes that appear only during collisions, extending understanding of soliton dynamics.

Findings

Spectral walls exist in antikink-kink collisions in the $^6$ model.

Delocalized modes trigger spectral walls during collisions.

Spectral walls are likely common in non-symmetric kink collisions in higher models.

Abstract

We show that thick spectral walls exist in antikink-kink collisions in the $\phi^6$ model. In this model, they are triggered by the so-called $delocalized$ $modes$ which do not exist in the single-soliton sector but emerge in antikink-kink ($\bar{K}K$) collisions. Therefore, spectral walls are a rather common phenomenon that should occur in many solitonic collisions involving non-symmetric kinks as, e.g., in the $\phi^8$ or higher power models.