![[PukiWiki]](image/pukiwiki.png "[PukiWiki]")
[[UTAPwiki/セミナー/初期宇宙・相対論速報]] *Title: Black hole information paradox and fine grained entropy in gravitational system [#qfadd9e0] **Speaker: Yusuke Yamada [#q7eeb6f9] Black hole information paradox has been one of the unsolved problems in quantum gravity. One can quantify the problem by looking at the behavior of the von Neumann entropy, which is also known as fine-grained entropy. Recently, the solution to the information paradox was proposed, which is the new rule to obtain improved fine-grained entropy formula in gravitational system. The improved formula gives the fine-grained entropy consistent with the unitarity. Interestingly, it can be derived by the semiclassical method, which is unexpectedly simple. In this talk, I will briefly review the information paradox and review the derivation of the fine-grained entropy formula in gravitational system, which is crucial to understand the recent proposals. If I have time, I will also explain how the expected behavior of the entropy, known as Page curve, is realized. (It is quite unlikely to have enough time, though.) Refs: A. Almheiri, T. Hartman, J. Maldacena, E.Shaghoulian, A. Tajdini, “The entropy of Hawking radiation” [2006.06872] A. Lewkowycz, J. Maldacena, “generalized gravitational entropy” [1304.4926] T. Faulkner, A. Lewkowycz, J. Maldacena, “Quantum corrections to holographic entanglement entropy” [1307.2892] X. Dong, A. Lewkowycz, “Entropy, extremality, euclidean variations, and the equations of motion” [1705.08453] A. Almheiri, T. Hartman, J. Maldacena, E.Shaghoulian, A. Tajdini, “Replica Wormholes and the Entropy of Hawking Radiation” [1911.12333] G. Penington, S. Shenker, D. Stanford, Z. Yang, “Replica wormholes and the black hole interior” [1911.11977] |