Spectral Walls at One Loop

TL;DR

This paper explores the quantum behavior of spectral walls in soliton moduli spaces, revealing that quantum effects cause repulsion of antikinks even without internal excitation, contrasting classical predictions.

Contribution

First analysis of spectral walls in a quantum setting, showing quantum repulsion effects differ from classical behavior.

Findings

Quantum repulsion of antikinks without internal excitation

Spectral walls do not produce classical-like effects in quantum theory

Quantum effects alter classical soliton interactions

Abstract

A spectral wall is a surface in a moduli space of classically BPS solitons where an internal excitation crosses the continuum mass threshold. It has recently been shown that spectral walls in classical field theory repel solitons whose corresponding internal excitations are excited. We investigate, for the first time, the fate of spectral walls in a quantum theory, calculating the instantaneous acceleration of a wave packet of classically BPS antikinks in the presence of an impurity. We find that, in the quantum theory, the antikinks are repelled even when the bound mode is not excited. Perhaps due to this repulsive force, the dramatic classical effects of the spectral wall are not seen in our quantum calculation.