In 1970s, Stephen Hawking raised a tension between general relativity and quantum mechanics in the black hole background: the famous black hole information paradox. During the past half-century, the black hole information paradox has been one of the biggest puzzles in theoretical physics and various efforts has been made to sharpen the information paradox. The most quantitative formulation of the information paradox concerns about the behavior of the entropy of the hawking radiation. From Hawking’s calculation, the entropy of hawking radiation keeps growing with time, while for a unitary system, the entropy should eventually vanish as argued by Don Page. In this talk, I will argue that a key ingredient called the replica wormhole, which was missed in Hawking’s original calculation, solves the entropy puzzle and leads to a unitary evolution. Based on work with Geoff Penington, Stephen Shenker and Douglas Stanford.

Zhenbin Yang received his PhD degree under the supervise of Professor Juan Maldacena from the Physics Department of Princeton University in June 2019. As a demonstration of the highest scholarly excellence in graduate work, Zhenbin was awarded the Charlotte Elizabeth Procter Fellowship from the Graduate School of Princeton University. Currently, Zhenbin is a Postdoc Fellow at the Stanford Institute for Theoretical Physics joined with the It From Qubit Fellow from the Simons Foundation. His research focuses on high energy theory, with an emphasis on the connection between quantum information, black hole information paradox and early universes. A few highlights of his work include the earliest development of the duality between Sachdev-Ye-Kitaev model and Jackiw-Teitelboim gravity, the study of traversable wormhole, and the resolution of Black Hole Information Paradox using replica wormholes.

Meeting Link: To request for meeting link, please write to phweb@ust.hk.