Decoding a black hole Speaker(s): Beni Yoshida
Abstract:
It is commonly believed that quantum information is not lost in a black hole. Instead, it is encoded into nonlocal degrees of freedom in some clever way; like a quantum errorcorrecting code. In this talk, I will discuss how one may resolve some paradoxes in quantum gravity by using the theory of quantum errorcorrection. First, I will introduce a simple toy model of the AdS/CFT correspondence based on tensor networks and demonstrate that the correspondence between the AdS gravity and CFT is indeed a realization of quantum codes. I will then show that the butterfly effect/scrambling in black holes can be interpreted as nonlocal encoding of quantum information and can be quantitatively measured by outoftime ordered correlations. Finally I will describe a simple decoding protocol for reconstructing a quantum state from the Hawking radiation and suggest a physical interpretation as a traversable wormhole in an AdS black hole. The decoding protocol also provides an attractive platform for laboratory experiments for measuring outoftime ordered correlation functions as it clearly distinguishes unitary scrambling from nonunitary decoherence. Date: 27/04/2017  2:00 pm
Series: Colloquium
