# Tachyons in the Galilean limit

## TL;DR

This paper explores the connection between tachyons and Galilean particles, showing that certain massless Galilean particles are limits of tachyonic models, and compares this with string theory limits.

## Contribution

It demonstrates that the Souriau massless Galilean particle is the Galilean limit of the Souriau tachyon, providing new insights into non-relativistic limits of tachyonic objects.

## Key findings

- Massless Galilean particles are limits of tachyons with imaginary mass.
- Comparison with string theory limits reveals similarities and differences.
- Provides a framework linking tachyons to non-relativistic particle models.

## Abstract

The Souriau massless Galilean particle of "colour" $k$ and spin $s$ is shown to be the Galilean limit of the Souriau tachyon of mass $m = ik$ and spin $s$. We compare and contrast this result with the recent Galilean limit of the Nambu-Goto string and the Green-Schwarz superstring.