Instability of Non-Commutative SYM Theories at Finite Temperature

TL;DR

This paper investigates the behavior of non-commutative N=4 U(1) Yang-Mills theory at finite temperature, revealing a phase transition characterized by a tachyonic mode and superluminal quasi-particle velocities.

Contribution

It extends previous work by identifying a critical temperature where a tachyon appears, indicating a phase transition in the non-commutative gauge theory.

Findings

Tachyonic collective transverse photon mode above critical temperature

Superluminal group velocities at low momentum

Evidence of a high-temperature phase transition

Abstract

We extend our previous work on the quasi-particle excitations in N=4 non-commutative U(1) Yang-Mills theory at finite temperature. We show that above some critical temperature there is a tachyon in the spectrum of excitations. It is a collective transverse photon mode polarized in the non-commutative plane. Thus the theory seems to undergo a phase transition at high temperature. Furthermore we find that the group velocity of quasi-particles generically exceeds the speed of light at low momentum.