Ann-Kathrin Straub | Searcharxiv

arXiv2017

Time dependence of entanglement for steady state formation in AdS$_3$/CFT$_2$

We consider a holographic model of two 1+1-dimensional heat baths at different temperatures joined at time $t=0$, such that a steady state heat-current region forms and expands in space for times $t>0$. After commenting on the causal structure of the dual 2+1-dimensional spacetime, we present how to calculate the time-dependent entanglement entropy of the boundary system holographically. We observe that the increase rate of the entanglement entropy satisfies certain bounds known from the literature on entanglement tsunamis. Furthermore, we check the validity of several non-trivial entanglement inequalities in this dynamic system.

hep-th↗

arXiv2017

Time evolution of entanglement for holographic steady state formation

Within gauge/gravity duality, we consider the local quench-like time evolution obtained by joining two 1+1-dimensional heat baths at different temperatures at time t=0. A steady state forms and expands in space. For the 2+1-dimensional gravity dual, we find that the shockwaves expanding the steady-state region are of spacelike nature in the bulk despite being null at the boundary. However, they do not transport information. Moreover, by adapting the time-dependent Hubeny-Rangamani-Takayanagi prescription, we holographically calculate the entanglement entropy and also the mutual information for different entangling regions. For general temperatures, we find that the entanglement entropy increase rate satisfies the same bound as in the "entanglement tsunami" setups. For small temperatures of the two baths, we derive an analytical formula for the time dependence of the entanglement entropy. This replaces the entanglement tsunami-like behaviour seen for high temperatures. Finally, we check that strong subadditivity holds in this time-dependent system, as well as further more general entanglement inequalities for five or more regions recently derived for the static case.

hep-th↗