BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Hong Liu (MIT) DTSTART:20200921T183000Z DTEND:20200921T193000Z DTSTAMP:20260423T005827Z UID:Kadanoff/10 DESCRIPTION:Title: Entanglement entropies of equilibrated pure states in quantum many-body systems and replica wormholes\nby Hong Liu (MIT) as part of Kadanoff s eminars\n\n\nAbstract\nWe develop a universal approximation for the Renyi entropies of a pure state at late times in non-integrable systems\, which macroscopically resembles an equilibrium density matrix. The resulting exp ressions are fully determined by properties of the associated equilibrium density matrix\, and are hence independent of the details of the initial s tate\, while also being manifestly consistent with unitary time-evolution. For equilibrated pure states in gravity systems\, such as those involving black holes\, this approximation gives a prescription for calculating ent anglement entropies using Euclidean path integrals which is consistent wit h unitarity and hence can be used to address the information loss paradox of Hawking. Applied to recent models of evaporating black holes and eterna l black holes coupled to baths\, it provides a derivation of replica wormh oles\, and elucidates their mathematical and physical origins. In particul ar\, it shows that replica wormholes can arise in a system with a fixed Ha miltonian\, without the need for ensemble averages.\n LOCATION:https://researchseminars.org/talk/Kadanoff/10/ END:VEVENT END:VCALENDAR