This book offers an overview of recent developments in holography, quantum chaos, and thermalization in quantum many-body systems. Its main focus is on the connection between thermalization in strongly coupled quantum systems and geometric structures in gravity, as described by the holographic correspondence.

In particular, the book explains how the eigenstate thermalization hypothesis, which provides a sufficient condition for thermalization in closed quantum systems, can be understood holographically in terms of universal gravitational objects such as black holes and wormholes. It also introduces a new holographic correspondence between open quantum systems and gravitational systems involving branes.

These results bear on fundamental questions in both high-energy physics and statistical physics, including the information problem in semiclassical gravity and the emergence of thermal behavior in quantum systems. The book provides the review of black hole thermodynamics, the AdS/CFT correspondence, and thermalization in closed and open quantum many-body systems. It is intended for researchers and graduate students in high-energy physics, statistical physics, and related areas.

Taishi Kawamoto received his Bachelor of Science from the Department of Physics II, Kyoto University in March 2021, and his Master of Science and Ph.D. from the Yukawa Institute for Theoretical Physics (YITP), Kyoto University in March 2023 and March 2026, respectively. He has been an Assistant Professor at the Hakubi Center for Advanced Research, Kyoto University since April 2026.