Non-conformal brane plane waves and entanglement entropy

TL;DR

This paper investigates entanglement entropy in non-conformal brane plane wave backgrounds, revealing how energy flux influences entanglement and phase transitions in dual gauge theories, with implications for string theory models.

Contribution

It extends holographic entanglement entropy analysis to non-conformal brane plane wave backgrounds, including phase transition indications and scale-dependent degrees of freedom.

Findings

Finite entanglement entropy depends on energy density and subsystem size.

Phase transitions are suggested for orthogonal strip configurations.

Effective degrees of freedom vary with scale and energy flux.

Abstract

Following [arXiv:1202.5935 [hep-th]] and [arXiv:1212.4328 [hep-th]], we study non-conformal brane plane wave backgrounds dual to strongly coupled gauge theories with constant energy flux and holographic entanglement entropy for strip subsystems in them. We find that for the strip direction along the direction of the energy flux, the finite cutoff-independent part of entanglement entropy can be estimated in terms of a dimensionless combination of the energy density and the strip dimensions, alongwith an effective scale-dependent number of degrees of freedom. For the strip orthogonal to the flux direction, there are indications of phase transitions. We also briefly discuss NS5-brane backgrounds corresponding to plane wave states in little string theories.