Wednesday, December 15, 13:30– 15:00 NEW WG Seminar
Wednesday, December 15, 17:00– 18:00 DMWG Seminar
Friday, December 17, 12:30- Coffee Meeting

On November 18, Yuka Suzuki from Okinawa Institute of Science and Technology (OIST) gave a talk titled "Spatial structure in ecology: the effects of dispersal network structure on biodiversity pattern and stability in metacommunities" at the iTHEMS Biology Seminar. She introduced the basic concepts of spatial structure in ecology and explained how computational tools and network theoretical concepts are used to investigate spatial structures in ecology using her own study. Her talk was easy to understand and also very interesting and stimulated many questions and discussions. I believe it was a very worthwhile time for many participants. Thanks Yuka!

Reported by Jeffrey Fawcett

On November 19, we invited Professor Shin-ichiro Seki from Aoyama Gakuin University to give a talk in the Math Seminar. He explained about the graph removal lemma, which is one of the key ingredients of the proof of his recent joint work with Kai, Mimura, Munemasa and Yoshino on a generalization of the celebrated Green-Tao theorem. In the first half of the talk, he gave a survey of Szemerédi's regularity lemma and the graph removal lemma, and explained how to extend the removal lemma to the case of (weighted) hypergraphs. In the second half of the talk, he presented Fox's result on a quantitative version of the graph removal, and discussed the prospects for future research. After the seminar, we had an online drinking party, and enjoyed a lot of discussion with the speaker.

Reported by Hiroyasu Miyazaki

Ryosuke Oketani from Kyushu University gave a talk on "Imaging Theory of Optical Microscopy: Basic to Super Resolution." Optical microscopy is a powerful tool to observe microscopic objects such as living micro-organisms. Recently, several super-resolution techniques have been developed, which enabled us to overcome the limit in spatial resolution caused by the wave nature of light. Ryosuke explained the basics and recent theoretical developments of optical microscopy and the super-resolution techniques. We also had fruitful discussions on the theory of optical microscopy from an interdiciplinary point of view.

Reported by Hidetoshi Taya

In November 26, there was a seminar by professor Kouichi Taira. He explained the relations between self-adjointness and the completeness of the classical dynamics. He especially explained a conjecture that self-adjointness and completeness of classical dynamics are equivalent. He then gave some examples on this conjectures.

Reported by Keita Mikami

In this week’s biology seminar, the invited speaker Prof. Hidetoshi Shimodaira introduced his recent work about selective inference. Selective inference is an important statistical problem described also by another word “the file-drawer effect”. For example, Journals are much more likely to publish studies with low P values, and the readers never hear about the great number of studies that showed no effect and were filed way. This makes it difficult to assess the strength of a reported P value. The challenge of correcting for the effects of selection is a complex one. Prof. Hidetoshi Shimodaira explained a method to improve the previously proposed approximately unbiased test by adjusting the selection bias. This method is applied to predict trees and edges in phylogeny. In the seminar, he started by an interesting introduction of Darwin's theory of evolution and the tree of life. Based on this theory, modern phylogenetic inference is developed by analyzing DNA sequences of species as system relationships like trees. He also showed us, different statistical tests can give different P values of trees and edges in the trees. Therefore, we should be careful doing the tests and aware of the bias types in the problem.
We thank Prof. Hidetoshi Shimodaira for his great talk and precious time with us!

Reported by Yingying Xu

Title: Most charming dibaryon near unitarity
Author: Yan Lyu, Hui Tong, Takuya Sugiura, Sinya Aoki, Takumi Doi, Tetsuo Hatsuda, Jie Meng, Takaya Miyamoto
arXiv: http://arxiv.org/abs/2112.01682v1

Title: Information Scrambling Versus Quantum Revival Through the Lens of Operator Entanglement
Author: Kanato Goto, Ali Mollabashi, Masahiro Nozaki, Kotaro Tamaoka, Mao Tian Tan
arXiv: http://arxiv.org/abs/2112.00802v1