On the Relevance of the Thermal Scalar

TL;DR

This paper explores the properties of near-Hagedorn string thermodynamics using the thermal scalar formalism, relating field theory aspects to string gas behavior in various spacetimes.

Contribution

It extends the thermal scalar approach to analyze stress tensor and charge properties of near-Hagedorn string gases in diverse backgrounds.

Findings

Found pressureless string gas in flat space near Hagedorn temperature

Identified non-zero string charge in AdS3

Derived thermal stress tensor in Rindler space

Abstract

We discuss near-Hagedorn string thermodynamics in general spacetimes using the formalism of the thermal scalar. Building upon earlier work by Horowitz and Polchinski, we relate several properties of the thermal scalar field theory (i.e. the stress tensor and U(1) charge) to properties of the highly excited or near-Hagedorn string gas. We apply the formulas on several examples. We find the pressureless near-Hagedorn string gas in flat space and a non-vanishing (angular) string charge in $AdS_3$. We also find the thermal stress tensor for the highly excited string gas in Rindler space.