Finite Temperature Gases of Fermionic Strings

TL;DR

This paper investigates the thermal behaviors and phase transitions of various fermionic string gases at finite temperature, revealing dualities, instabilities, and phase transition mechanisms including a Kosterlitz-Thouless transition.

Contribution

It provides a detailed analysis of thermal dualities, phase transitions, and stability properties of fermionic string gases, including the identification of an order parameter for the Kosterlitz-Thouless transition.

Findings

Type IIA and IIB string gases exhibit thermal duality and tachyonic instabilities.

Heterotic string gas is tachyon-free with a self-dual phase transition.

Identification of the Kosterlitz-Thouless transition order parameter.

Abstract

We show that in the absence of a Ramond-Ramond sector both the type IIA and type IIB free string gases have a thermal instability due to low temperature tachyon modes. The gas of free IIA strings undergoes a thermal duality transition into a gas of free IIB strings at the self-dual temperature. The free heterotic string gas is a tachyon-free ensemble with gauge symmetry SO(16)$\times$SO(16) in the presence of a timelike Wilson line background. It exhibits a holographic duality relation undergoing a self-dual phase transition with positive free energy and positive specific heat. The type IB open and closed string ensemble is related by thermal duality to the type I' string ensemble. We identify the order parameter for the Kosterlitz-Thouless phase transition from a low temperature gas of short open strings to a high temperature long string phase at or below T_C. Note Added (Sep 2005).