UAAT International Young Visiting Scholar Program
Shohei Satake
Associate Professor
Kumamoto University
Email: shohei-satake@kumamoto-u.ac.jp
Webpage: https://sites.google.com/site/satakeshohei/
Host Scholar: Shagnik Das, Assistant Professor
Hosting Department/Institution: Department of Mathematics, National Taiwan University
Biography:
Shohei Satake received a Master's degree in Information Science from Nagoya University, Japan, in March 2017, and a Ph.D. degree from Kobe University, Japan, in March 2020. From April 2020 to March 2022, he was a research fellow (PD) at the Japan Society for the Promotion of Science. After serving as an assistant professor at Meiji University, Japan, he became an associate professor at Kumamoto University, Japan, in March 2023. His current research interests include combinatorics and its applications, particularly spectral graph theory and its interactions with information and computer sciences.
Lecture [1]:
Time: Friday, March 21, 11:20 A.M.
Venue: Room 505, Cosmology Building, NTU
Title: Restricted Isoperimetry Property Matrices and Paley Graphs
Abstract:
A matrix with the Restricted Isometry Property (RIP) is a central object in compressed sensing theory, and constructing such matrices is a challenging problem. On the other hand, Paley graphs have played a significant role in Ramsey theory, and understanding their structure remains a major open problem in combinatorics and number theory. In this talk, we review these backgrounds and demonstrate that the RIP of certain matrices provides a sharp estimation for the discrepancy of Paley graphs. Under this result, we consequently obtain a sharp estimation of the clique number of Paley graphs as well.
Lecture [2]:
Time: Friday, March 28, 11:20 A.M.
Venue: Room 505, Cosmology Building, NTU
Title: Explicit constructions of expander graphs with improved spectral gaps
Abstract:
Expander graphs are highly connected yet sparse, playing a crucial role in various areas of mathematics and computer science. In particular, constructing explicit expander graphs, especially those with a small spectral gap, is a fundamental but challenging problem. In this talk, we present new explicit constructions of graphs with improved spectral gap estimates, refining a construction by Alon (2020).