Entanglement Entropy for Probe Branes

TL;DR

This paper presents a systematic holographic method to compute entanglement entropy in probe brane systems, accounting for leading order backreaction, validated by exact models and applied to D3/D7 and D3/D5 setups.

Contribution

It introduces a simple double integral formula for entanglement entropy in probe brane systems that is largely insensitive to complex backreaction details.

Findings

Validated the method against solvable toy models.

Computed entanglement entropy for sphere and strip in D3/D7 and D3/D5 systems.

Found perfect agreement with existing results for the sphere case.

Abstract

We give a prescription for calculating the entanglement entropy in holographic probe brane systems by systematically taking the leading order backreaction of the probe brane into account. We find a simple compact double integral formula, which is insensitive to many details of the backreaction, most notably the internal space or the non-metric fields sourced by the probe. We validate our method by comparing to exact results in solvable toy models. We also determine the entanglement entropies for a sphere and a strip in the top-down D3/D7 and D3/D5 system. For the sphere the entanglement entropy has also been obtained by other methods and we find perfect agreement.