RIKEN's pamphlet "RIKEN at a Glance 2022" features iTHEMS and the newly opened RIKEN-Berkeley Center.

Please see the related link for details.

Prof. Yasunori Nomura, the director of the Berkeley Center for Theoretical Physics, the University of California, Berkeley, visited iTHEMS and gave a colloquium entitled “From the Black Hole Conundrum to the Structure of Quantum Gravity” on July 26th. Prof. Nomura started the colloquium by explaining that the two pillars of modern physics, quantum mechanics and general relativity are actually at odds with each other, but each of them usually governs a different domain of physical phenomena, thus obscuring the incompatibility. The focus of the colloquium lies on one of the areas where both quantum mechanics and general relativity become equally important, namely quantum theory of black holes. Prof. Nomura illustrated how the famous phenomenon of black holes discovered by Stephen Hawking, Hawking radiation leads to so-called information paradox, in which the conservation the probability appears to be violated during the process of the radiation from the horizon. He went on to describe the key ingredients in solving the paradox, which are the concept of holography, the stretched horizon, and AdS/CFT correspondence.

In the latter part of the colloquium, Prof. Nomura pedagogically showed the audience the most recent development in the study of the information paradox. The calculation including the contribution from “wormholes” was shown to reproduce the Page curve implying the recovery of the lost probability. The same calculation was also explained through formalism which was developed by Prof. Nomura himself. He concluded with the message that the study of the black hole conundrum is thus revealing the structure of quantum gravity, which involves with a wide range of various research fields such as high energy physics and astrophysics, quantum information science, and many-body physics.

The colloquium was taken place at the 2F Large Meeting Room of RIBF Building and was attended by a limited number of audience in person due to the wide spreading of COVID-19, but more than eighty people joined through zoom.

Reported by Tsukasa Tada

Dr. Namiko Mitarai (Niels Bohr Institute) gave us an amazing talk in the biology seminar. She told us about the collaborative works with experimental biologists on a microbial world. Some viruses that infect bacteria are known to provide immunity to infection by the same virus. According to her, no-immune bacteria can be protected from infection when the ratio of immune bacteria is substantially high in the population, which reminds us of our current cases for Covid-19. Interestingly, the metabolic state of host (bacteria) also affects the virus infection. The talk was very very exciting. In the end of her seminar, she also showed us the tips for the successful collaboration with experimental biologists: (1) We (theorists) should care about them. (2) They (experimental biologists) should care about us. During and after the talk, there were lively discussion between the speaker and iTHEMS researchers. Thanks Mitarai-san!!

Reported by Gen Kurosawa

Title: Ceratozamia schiblii (Zamiaceae): A new cycad species from the eastern mountains of Oaxaca, Mexico
Author: Miguel Angel Pérez-Farrera, José Said Gutiérrez-Ortega, Timothy J. Gregory, Jeffrey Chemnick, Silvia Salas-Morales, Michael Calonje, Pedro Díaz-Jiménez
Journal Reference: Taxonomy 2(3):324-338 (2022)
doi: https://doi.org/10.3390/taxonomy2030025

Title: New developments in relativistic magnetohydrodynamics
Author: Koichi Hattori, Masaru Hongo, Xu-Guang Huang
arXiv: http://arxiv.org/abs/2207.12794v1