Superstring entanglement at finite temperature and its Hagedorn behavior

TL;DR

This paper introduces a finite-temperature superstring density matrix to analyze entanglement entropy, revealing Hagedorn behavior through modular functions, advancing understanding of string thermodynamics.

Contribution

It defines a superstring extended density matrix at finite temperature and links entanglement entropy to Hagedorn phenomena using modular functions.

Findings

Entanglement entropy expressed via modular functions.

Identification of Hagedorn behavior in string entanglement.

Extension of density matrix formalism to superstrings at finite temperature.

Abstract

This work demonstrates that a superstring extended density matrix can be defined at finite temperature. This enables the calculation of the extended entanglement entropy between string coordinates. Using a real-time approach, the entanglement entropy is expressed in terms of modular functions, whose proprieties are then used to study Hagedorn behavior.