String Free Energy, Hagedorn and Gauge/String Duality

TL;DR

This paper models string free energy to resemble QCD behavior, showing a crossover without a limiting temperature, using string-based effective descriptions.

Contribution

It provides examples of string models that mimic QCD thermodynamics, highlighting a crossover without a limiting temperature.

Findings

String free energy exhibits power-law behavior at high temperature.

String free energy decreases exponentially at low temperature.

No limiting temperature exists in the modeled string systems.

Abstract

We give examples of modeling the string free energy whose behavior mimics that of QCD: a power-law at high temperature and an exponential decrease at low temperature. Although the effective description is in terms of strings, no limiting temperature exists, as expected for a crossover.