Academic Staff and Fellows

TASAKA Koji: Associate Professor Ph.D. (Mathematical Sciences); Department/Science　
Department of Science
Graduate school/Science

Number theory is the study of numbers -- things like prime numbers and integers, and the patterns they follow. But if we look closely at numbers, we find that they are connected to many other areas of mathematics and mathematical physics, such as algebra, analysis, geometry, and combinatorics. In our laboratory, we work on several different topics -- multiple zeta values, modular forms, and spherical designs -- and look for surprising connections between them, hidden within the world of numbers.

Research Area	Number Theory, Combinatorics,
Research Interests	- Modular phenomena for multiple zeta values - Finite periods - Algebraic structure of multiple zeta values arising from the double shuffle relations - Analytic and algebraic study of multiple Eisenstein series - Classification of finite subsets on the sphere via spherical designs
Selected Publications	1. H. Bachmann, K. Tasaka, The double shuffle relations for multiple Eisenstein series, Nagoya Math. J., 230 (2018.06), 180--212. 2. H. Bachmann, K. Tasaka, Y. Takeyama, Cyclotomic analogues of finite multiple zeta values, Compositio Math., 154(12) (2018.12), 2701--2721. 3. D. Ma, K. Tasaka, Relationships between multiple zeta values of depths 2 and 3 and period polynomials, Isr. J. Math., 242(1) (2021.04), 359--400. 4. M. Hirao, H. Nozaki, K. Tasaka, Spherical designs and modular forms of the D4 lattice, Research in Number Theory, 9(4) (2023.11), Article number: 77. 5. J. Rosen, Y. Takeyama, K. Tasaka, S. Yamamoto, The ring of finite algebraic numbers and its application to the law of decomposition of prime, J. Number Theory, 263 (2024.10), 335--365.
Affiliated Academic Societies	The Mathematical Society of Japan
Education (Undergraduate Course)	Kindai University
Education (Master's/Doctral Course)	Kyushu University
Title of Thesis, Institute, Date	A Study on Multiple Zeta Values Related to Periods of Elliptic Modular Forms，Kyushu University，March 2014
Biography	July 2014 -- March 2015, Post-doctoral fellowship (hosted by Prof. YoungJu Choie), Pohang Mathematical Institute, Pohang University of Science and Technology, Korea April 2015 -- March 2016, JSPS Research Fellow PD (hosted by Prof. Kohji Matsumoto), Graduate School of Mathematics, Nagoya University April 2016 -- March 2024, School of Information Science and Technology, Aichi Prefectural University April 2017 -- February 2018, Guest Scientist, Max Planck Institute for Mathematics, Germany

E-mail	tasaka（at）math.kindai.ac.jp Note that this e-mail address has replaced the "@" with "(at)" to prevent spam. When e-mailing, replace the "(at)" with "@".
Laboratory URL	https://www.math.kindai.ac.jp/laboratory/tasaka/