**Shizuo Kakutani** was a Japanese-born American mathematician who worked in probability theory, ergodic theory and complex analysis, and is best known for his fixed-point theorem.

- Seiichi studied physics at Kyoto University and it was through him that Shizuo was first introduced to mathematics.
- Shizuo was fascinated and was enthusiastic to learn more mathematics.
- The first problem was that Kakujiro Kakutani had made the decision that one of his two sons would follow him into law and take over his practice in due course.
- After completing his middle school, Shizuo entered Konan High School in Kobe to prepare for his university studies.
- However, Shizuo was now not qualified to enter a mathematics course at either the University of Tokyo or Kyoto University since these had absolute rules regarding entry qualifications.
- There was one possible route for Shizuo which was to enter Tohoku University in Sendai.
- Kakutani applied but there were only fifteen places, and seventeen applicants.
- Of the seventeen, exactly fifteen had the science qualification from high school so it looked like an easy task to decide to admit those and to turn down Kakutani.
- However, after due consideration it was decided to admit all seventeen applicants and Kakutani had scrape through.
- At Tohoku University Kakutani was introduced to the theory of analytic functions.
- Indeed on the strength of this work Weyl invited Kakutani in 1940 to spend two years at the Institute for Advanced Study at Princeton.
- Kakutani not only took great interest in the work of Weyl's group at Princeton but also the group of mathematicians working with von Neumann on measure theory and ergodic theory.
- Kakutani also made many visits during which he met mathematicians such as Garrett Birkhoff, G D Birkhoff, Stone, Wiener, and Hille.
- In December 1941 with Kakutani still studying at Princeton, war broke out between the United States and Japan with the entry of the U.S.A. into the Second World War.
- Of course this put Kakutani in a difficult position for he was now a guest in a country at war with his own.
- What, you may wonder, did Kakutani do.
- On his return to Japan Kakutani accepted the appointment as assistant professor at Osaka University.
- Kakutani, however, managed to continue to produce a stream of papers containing highly original ideas.
- In 1948 Kakutani was again invited to the Institute for Advanced Study at Princeton.
- Kakutani contributed to several areas of mathematics.
- Kakutani was to remain at Yale until he retired in 1982.

Born 28 August 1911, Osaka, Japan. Died 17 August 2004, New Haven, Connecticut, USA.

View full biography at MacTutor

Origin Japan

**Oâ€™Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive