Title:
“Entanglement entropy at strong coupling – thermalisation and expanding spacetimes”
Abstract:
In this seminar I will present two recent results on entanglement in strongly coupled QFTs. First I will introduce the thermalisation of entanglement of generic entangling regions after a quench [1]. Depending on the ratio of the axes of ellipsoids the entanglement entropy thermalises with either the entanglement velocity or with the butterfly velocity. The butterfly velocity is an upper bound for thermalisation and we show that this upper bound is saturated for a large class of entangling regions. The second part of the talk will be about entanglement entropy in empty 4-dimensional de Sitter spacetime of a non-conformal QFT [2]. Interestingly, we show that extremal surfaces in the holographic dual of spherical entangling regions on the boundary QFT probe beyond the dual event horizon if and only if the entangling region is larger than the cosmological horizon.
[1] Márk Mezei and WS, Black holes often saturate entanglement entropy the fastest, 2001.03172 (PRL)
[2] Jorge Casalderrey-Solana, Christian Ecker, David Mateos and WS, Strong-coupling dynamics and entanglement in de Sitter space, 2011.08194
Slides: