String Entanglement and D-branes as Pure States

TL;DR

This paper investigates the entanglement of closed string degrees of freedom to understand the microscopic structure of D-branes, revealing how boundary states emerge in the pure state limit and exploring thermal properties and dissipative effects.

Contribution

It introduces a novel analysis of string entanglement to recover boundary states and describe brane thermodynamics within a pure state framework.

Findings

Boundary states are recovered in the zero entanglement entropy limit.

The collapse of closed string descriptions occurs in the pure state limit.

Thermal properties of branes are modeled with dissipative effects included.

Abstract

We study the entanglement of closed strings degrees of freedom in order to investigate the microscopic structure and statistics of objects as D-branes. By considering the macroscopic pure state (MPS) limit, whenever the entanglement entropy goes to zero (in such a way that the macroscopic properties of the state are preserved), we show that boundary states may be recovered in this limit and, furthermore, the description through closed string (perturbative) degrees of freedom collapses. We also show how the thermal properties of branes and closed strings could be described by this model, and it requires that dissipative effects be taken into account. Extensions of the MPS analysis to more general systems at finite temperature are finally emphasized.