Shock-Free Wave Propagation in Gauge Theories

TL;DR

This paper investigates conditions for shock-free wave propagation in gauge theories, extending the 'completely exceptional' approach to higher dimensions and analyzing various field models to identify physically acceptable actions.

Contribution

It generalizes the 'completely exceptional' method to higher dimensions and applies it to scalar, vector, and gravity models to determine shock-free propagation criteria.

Findings

Derived shock-free propagation conditions for various gauge fields.

Characterized physically acceptable actions avoiding shocks.

Extended the 'completely exceptional' approach to higher-dimensional systems.

Abstract

We present the shock-free wave propagation requirements for massless fields. First, we briefly argue how the "completely exceptional" approach, originally developed to study the characteristics of hyperbolic systems in 1+1 dimensions, can be generalized to higher dimensions and used to describe propagation without emerging shocks, with characteristic flow remaining parallel along the waves. We then study the resulting requirements for scalar, vector, vector-scalar and gravity models and characterize physically acceptable actions in each case.