**Zyoiti Suetuna** was a Japanese mathematician who worked mainly in number theory.

- At the First High School Suetuna's mathematical talents became clear to his teachers and in 1919 he entered Tokyo University to take a degree in mathematics.
- When Suetuna was in his final undergraduate year his studies were supervised by Takagi and this inspired Suetuna to work on number theory.
- This paper formed the basis for the first sixteen of Suetuna's papers which were on LLL-functions (generalisations of the zeta function) and appeared from 1924 up to 1931.
- Suetuna taught for two years at Kyushu University, being promoted to associate professor during that period, then returned to Tokyo University in 1924.
- In 1927 Suetuna went to study in Europe, in particular spending two years at Göttingen with Landau's school.
- The style of mathematical research carried out by this group with its lively discussion seminars impressed Suetuna so much that he went on to introduce this research style to Japan on his return.
- Now 1927, the year Suetuna went to Europe, was the one in which Artin published his general reciprocity law which in some sense completed the proofs of the ideas Takagi had introduced in 1920.
- Suetuna was fascinated by this result of Artin and he went to Hamburg in 1929 to study with him.
- Hasse was also proving important results in this area and Suetuna collaborated with Hasse visiting him in Halle in 1929 to complete work on their joint paper A general divisor problem.
- The European trip had been extremely productive for Suetuna and when he returned to Tokyo University in 1931 he had gained greatly from the experience.
- Suetuna did not spent a great deal of time attending lectures on probability and statistics, preferring to work on his own research topics.
- Back in Japan Suetuna introduced a weekly seminar on the Göttingen style where new research results could be discussed.
- Suetuna was appointed to Takagi's chair in 1936 when Takagi retired; Suetuna had been promoted to full professor in the previous year.
- The Second World War disrupted life in Japan and in particular it essentially ended Suetuna's research career.
- These eight publications make Suetuna an important figure in Buddhist philosophy and probably mean that he is more famous for that topic than he is for mathematics.
- Suetuna was elected to the Japan Academy in 1947.

Born 28 November 1898, Kunisaki, South Island, Japan. Died 6 August 1970, Tokyo, Japan.

View full biography at MacTutor

Origin Japan

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive