Five-point Superluminality Bounds

TL;DR

This paper derives new bounds on superluminal propagation for scalar five-point interactions, connecting them to four-point bounds and extending the analysis to higher-point interactions.

Contribution

It introduces the first superluminality bound for scalar five-point interactions and relates it to existing four-point bounds, extending the framework to higher-point interactions.

Findings

Established a superluminality bound for five-point interactions

Showed equivalence between five-point and four-point bounds

Extended the analysis to higher-point interactions

Abstract

We investigate how the speed of propagation of physical excitations is encoded in the coefficients of five-point interactions. This leads to a superluminality bound on scalar five-point interactions, which we present here for the first time. To substantiate our result, we also consider the case of four-point interactions for which bounds from S-matrix sum rules exist and show that these are parametrically equivalent to the bounds obtained within our analysis. Finally, we extend the discussion to a class of higher-point interactions.