# Huygens' principle and Dirac-Weyl equation

## TL;DR

This paper examines the validity of Huygens' principle in the massless Dirac-Weyl equation across different spatial dimensions, providing explicit solutions for specific cases and discussing broader implications.

## Contribution

It offers a detailed analysis of Huygens' principle for the Dirac-Weyl equation, highlighting its dimension-dependent validity and comparing it with the Klein-Gordon equation.

## Key findings

- Huygens' principle holds for odd space dimensions.
- Huygens' principle is invalid for even space dimensions.
- Explicit solutions are provided for n=1,2,3 cases.

## Abstract

We investigate the validity of Huygens' principle for forward propagation in the massless Dirac-Weyl equation. The principle holds for odd space dimension n, while it is invalid for even n. We explicitly solve the cases n=1,2 and 3 and discuss generic $n$. We compare with the massless Klein-Gordon equation and comment on possible generalizations and applications.