I am a professor at Institute of Mathematics, University of Tsukuba. My research interests are in Hopf algebras, (super)group schemes, Galois theory and tensor categories;
a reviewer of the AMS Reviews;
on the editorial boards of the following journals:
Journal of Mathematical Society of Japan;
PUMP Journal of Undergraduate Research;
Tsukuba Journal of Mathematics.
I am retiring in two years. So, basically, I am not able to accept graduate students anymore.
NEWS
In September, 2025, Nippon Hyoronsha CO., LTD. 日本評論社 has published a book entitled "Anonymous Question Box for University Maths" 大学数学質問箱, 群・環・体・ガロア理論 篇. It contains my brief article on Differential Galois Theory, which once appeared in 数セミ, and was revised to some extent in this occasion; in particular, added are references to 西岡久美子『微分体の理論』共立出版，西岡斉治『代数的差分方程式ー差分体の応用』数学書房．
On August 25th, 2025, "One-day Meeting on Group Schemes and Hopf Algebras" was held at Tsukuba; it was dedicated to the memory of Professor Noriyuki Suwa. The speakers include Dr. Michio Amano and Dr. Yuji Tsuno, the two of whom share a strong bond with Professor Suwa.
Dr. Li Kangqiao, Lecturer at Hangzhou Normal University, had a research stay at Tsukuba as a Visiting Foreign Research Fellow, from April 25th to August 24th, 2025. He is an active young mathematician working in the research area of Hopf algebras and tensor categories. His recent achievements in theory of partially dualized quasi-Hopf algebras are noteworthy.
Prof. Ivan Tomasic at London will be giving again a seminar talk on December 11th, 2024; it is entitled "Galois theory of differential schemes".
Yuta Takahashi was awarded the degree of Doctor of Philosophy. At the graduation ceremony held on March 25, 2024, he was also awarded the Dean's Prize and the Esaki Reona Prize. He starts working at NIT(Kosen), Numazu College.
A guidance book of mathematics for freshmen 「大学数学ガイダンス」 has been published from Nippon Hyoronsha CO., LTD. 日本評論社 in March 2024, which contains my brief article introducing Galois Theory, entitled "Galois Theory --- Experience tour for a behavioral principle in mathematics”.
Prof. Ivan Tomasic at London will be giving a seminar talk on difference and differential Galois theories on September 4th, 2023.
Eric Müller, a good fried of mine for 30 years, who is now leading the International Mathematical Olympic, will give a seminar talk at University of Tsukuba on May 29, Monday.
My brief article on Differential Galois Theory appeared in a Japanese popular mathematical magazine, 数学セミナー2022年6月号 (Sugaku Seminar, 2022 June Issue).
An introductory textbook on linear algebra written by myself in Japanese is published from the Science-Sha BPC: ガイダンス線形代数（増岡 彰）サイエンス社
Again, together with T. Hayashi and H. Yamane, I will be organizing an international Hopf-algebra conference, H-ACT2019, at Tsukuba in March 25--27, 2019; For more details please see [here].
"One-day meeting on Hopf algebras and group schemes" will be held at University of Tsukuba. Natural Science Bld. Room 814. on November 5, 2018. The speakers includes Prof. Noriyuki Suwa (Chuo Univ.), Prof. Kenichiro Kimura and Prof. Tomoki Mihara (U. Tsukuba). Program [here]
Together with T. Hayashi and H. Yamane, I will be organizing an international Hopf-algebra conference, H-ACT, at Tsukuba in September 2016; For more details please see [here].
An intensive course by Prof. Noriyuki Suwa on algebraic geometry will be given at Tsukuba on January 23-25, 2017; For more details please see [here].