Unitarization and Causalization of Non-local quantum field theories by Classicalization

TL;DR

This paper proposes that classicalization, through the formation of classicalons, can resolve acausal divergences in non-local quantum field theories, thereby restoring unitarity and causality in scattering processes.

Contribution

It introduces a novel approach where classicalization is used to unitarize and causalize non-local quantum field theories by forming classicalons during scatterings.

Findings

Classicalons can prevent acausal divergences in non-local QFTs.

Classicalization restores unitarity and causality in scattering amplitudes.

The approach is demonstrated in the trans-non-local limit.

Abstract

We suggest that classicalization can cure non-local quantum field theories from acausal divergences in scattering amplitudes, restoring unitarity and causality. In particular, in "trans-non-local" limit, the formation of non-perturbative classical configurations, called {\it classicalons}, in scatterings like $\phi\phi\rightarrow \phi\phi$, can avoid typical acausal divergences.