Takeshi OGASAWARA

Department of Mathematics and Statistics, Premedical Sciences

Dokkyo Medical University,

880 Kitakobayashi, Mibu, Shimotsuga, Tochigi, 321-0293, JAPAN

Email: t-ogswr `at' dokkyomed.ac.jp

Research Interests

Algebraic number theory, Automorphic forms

Thesis

A study on elliptic modular forms of weight one, March, 2012, Kyushu University

Refereed Papers

1. On PGL2(F7) and PSL2(F7) number fields ramified at a single prime (with George J. Schaeffer). Journal of Number Theory, Vol. 267 (February, 2025), 202--220. 

2. Some expressions for binary theta series by eta-quotients and their applications. Journal of Number Theory, Vol. 186 (May, 2018), 493--509.

3. On Hecke modules generated by eta-products and imaginary quadratic fields. Proceedings of the American Mathematical Society, Vol. 145, no. 1 (Jan., 2017), 23--37. 

4. A certain eta-quotient and the class number of an imaginary quadratic field. International Journal of Number Theory, Vol. 10, no. 6 (Sep., 2014), 1485--1499.

5. Appendix in F. Amano, H. Kodani, M. Morishita, T. Sakamoto, and T. Yoshida, Redei's triple symbols and modular forms, with an appendix by T. Ogasawara, Tokyo Journal of Mathematics, Vol. 36, no. 2 (Dec., 2013), 405--427. 

6. Octahedral newforms of weight one associated to three division points of elliptic curves. Functiones et Approximatio, Commentarii Mathematici, Vol. 49, no. 1 (Sep., 2013), 103--109. Adam Mickiewicz University.

7. An eigenform of weight one expressed by meromorphic η-quotients. The Ramanujan Journal, Vol. 27, no. 1 (Jan., 2012), 89--99.

Talks at International Conference

1. Eta-quotients and class numbers of imaginary quadratic fields, 26th Automorphic Forms Workshop, University of British Columbia, Vancouver, Canada, April, 2012.

2. Eta-quotients of weight one and ideal class groups of imaginary quadratic fields, Workshop on Modular Forms, Kyushu University, May, 2012.

3. On Hecke modules generated by eta-quotients of weight one, Modular functions and Quadratic forms -- Number theoretic delights, Osaka University Nakanoshima Center, December 21 (Sat) -- December 23 (Mon), 2013．

4. Some topics on mod p modular forms of weight one, The 17th MSJ-SI Modular Forms and Multiple Zeta Values, Kindai University, February 17 -- February 22, 2025. 

5. Searching for PGL(2,7) number fields with a single ramified prime, Low dimensional topology and number theory XVI, In honor of Professor Hiroaki Nakamura's 60th birthday, Osaka University, March 25 -- March 28, 2025.