# Kavli IPMU Visiting Senior Scientist Tadashi Takayanagi Receives Nishina Memorial Prize

November 1, 2016

Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU)

Kavli IPMU Visiting Senior Scientist and Kyoto University Yukawa Institute for Theoretical Physics Professor Tadashi Takayanagi has been awarded the 2016 Nishina Memorial Prize. Commemorating the achievements of the late Dr. Yoshio Nishina, the Nishina Memorial Prize honors young researchers who have outstanding attainments in nuclear physics research and application.

Six notable Japanese who have won the Nobel Prize in Physics, namely Reona Esaki, Masatoshi Koshiba, Makoto Kobayashi, Toshihide Masukawa, Shuji Nakamura, and Takaaki Kajita, have also received the award.

Moreover, Kavli IPMU Principal Investigator, California Institute of Technology Professor, Caltech Walter Burke Institute for Theoretical Physics Director, and Aspen Center for Physics Director Hirosi Ooguri, won the award in 2009, as did Kavli IPMU Principal Investigator and Tohoku University Research Center for Neutrino Science Professor Kunio Inoue.

This time, Takayanagi received the Nishina Memorial Prize for his “discoveries in—and development of—holographic entanglement entropy formula.”

Based on theories of black hole entropy, the holographic principle—which was established within the framework of string theory in 1997—has had significance in superstring theories. The concept of entanglement (or quantum entanglement) plays an important role in quantum mechanics, quantum information theory, and condensed matter physics, while entanglement entropy is a measure of how much a given quantum state is entangled.

Announced in 2006 by Takayanagi (and co-author Shinsei Ryu), holographic entanglement entropy formulas calculate entanglement entropy using theories of gravity. Based on the holographic principle, it describes entanglement entropy by linking it to the geometric character of gravitational theories.

Known as the Ryu-Takayanagi Formula, and developed over some 10 years, the calculations and its development have elucidated our understanding of holographic entanglement entropy, and made significant contributions to theoretical physics.

Upon receiving the Nishina Memorial Prize, Takayanagi said: “I am very honored to receive this prestigious prize which appreciates that we opened up an interdisciplinary field between string theory and quantum information theory. I am very grateful to my collaborators, especially Shinsei Ryu.

“Taking this great opportunity, I would like to make greater efforts in developing related subjects. It is also my pleasure if, in receiving this award, I can encourage young researchers who are challenging new interdisciplinary fields in theoretical physics.”

**Related links:**

Tadashi Takayanagi, Kyoto University Yukawa Institute for Theoretical Physics