Stability of hot tachyon gas

TL;DR

This paper analyzes the stability and sound speed of a hot tachyon gas obeying Maxwell-Boltzmann statistics, showing it remains causal with sound speed limits depending on temperature.

Contribution

It provides a detailed study of the sound speed behavior and causality conditions in a hot tachyon gas across different temperature regimes.

Findings

Sound speed remains subluminal at all temperatures.

Sound speed approaches 1/√2 at low temperatures.

Sound speed approaches 1/√3 at high temperatures.

Abstract

We consider a tachyon gas that obeys Maxwell-Boltzmann statistics. The sound speed is always subluminal and it tends to the limiting minimum value $c_s=1/\sqrt{2}$ in non-relativistic gas (at low temperature), decreasing monotonously with the growth of temperature and attaining ultra-relativistic limit $c_s=1/% \sqrt{3}$ at high temperature. The hot tachyon gas always satisfies the causality.