Title：Radiation, entanglement and islands from a boundary local quench

Speaker：Marco Meineri，the University of Geneva

Time：Aug.18, 2022 14:30-16:00

Venue：302，Physics Building

Online report（ Zoom ID：884 7246 5350 ）

Abstract： Out-of-equilibrium states in conformal field theories (CFT) are relevant both in condensed matter and in holography. In particular, CFTs with a boundary have proven to be a useful playground to study entanglement in quantum gravity. Here, we describe the entanglement and the energy density of the radiation emitted after a local quench in a boundary CFT. We show that the early- and late-time behaviors of the entanglement entropy are controlled by a convergent operator product expansion (OPE) and are---under mild assumptions---universal. We also derive a rigorous upper bound on the entanglement, valid along the full time evolution. These CFT predictions are then compared with a doubly-holographic setup, where the CFT is interpreted as a reservoir for the radiation produced on an end-of-the-world brane. Along the way, we elucidate the holographic dictionary for boundary CFT. In the brane+bath picture, the formation of an island is responsible for preserving unitarity at late time, and the holographic computation of the entanglement entropy is explicitly reproduced by the island formula.

Brief Bio：Professor Marco Meineri received his Ph.D. from SNS in 2016, and subsequently, he worked at EPFL and CERN. Now he is an Ambizione fellow at the University of Geneva. Professor Marco Meineri’s main activity revolves around the effects of boundaries and defects in quantum and conformal field theories, with their various applications to condensed matter, holography, quantum information.