is a Japanese mathematician.

Life

Sakai studied mathematics at the Tohoku University (Sendai). He there received the B. A. degree in 1953 and a doctorate at the same University in 1961. From 1960 to 1964, he was a faculty member of

Waseda University , abbreviated as , is a private university, private research university in Shinjuku, Tokyo. Founded in 1882 as the ''Tōkyō Senmon Gakkō'' by Ōkuma Shigenobu, the school was formally renamed Waseda University in 1902. The university has numerou ...

. He then went to the

University of Pennsylvania The University of Pennsylvania (also known as Penn or UPenn) is a private research university in Philadelphia. It is the fourth-oldest institution of higher education in the United States and is ranked among the highest-regarded universitie ...

, where he became a professor in 1966 and remained until 1979. He then returned to Japan and went to the

Nihon University , abbreviated as , is a private university, private research university in Japan. Its predecessor, Nihon Law School (currently the Department of Law), was founded by Yamada Akiyoshi, the Minister of Justice (Japan), Minister of Justice, in 1889. ...

. In 1992, he received the Japanese Mathematical Society Autumn Prize. He is a fellow of the

American Mathematical Society The American Mathematical Society (AMS) is an association of professional mathematicians dedicated to the interests of mathematical research and scholarship, and serves the national and international community through its publications, meetings, ...

. Sakai's main field is

functional analysis Functional analysis is a branch of mathematical analysis, the core of which is formed by the study of vector spaces endowed with some kind of limit-related structure (e.g. Inner product space#Definition, inner product, Norm (mathematics)#Defini ...

and

mathematical physics Mathematical physics refers to the development of mathematics, mathematical methods for application to problems in physics. The ''Journal of Mathematical Physics'' defines the field as "the application of mathematics to problems in physics and t ...

. His textbook published in the Springer series in C *-algebras and W *-algebras, in which W *-algebras as C *-algebras are introduced with a predual, is widely used. That fact the W *-algebras may be defined in this way is known as a theorem of Sakai (cf. a theorem of Kadison-Sakai.)George A. Elliot: ''On derivations of AW*-algebras'', Tóhoku Mathematical Journal, Band 30 (1978), Seiten 263–276.

Works

*''C *-algebras and W *-algebras'', Springer-Verlag 1971, Ergebnisse der Mathematik und ihrer Grenzgebiete, Volume 60, (republished in 1998 in ''Classics in Mathematics'') *''Operator algebras in dynamical systems, the theory of unbounded derivations in C*-algebras,'' Cambridge University Press (1991),

References

{{DEFAULTSORT:Sakai, Shoichiro 1928 births Living people 20th-century Japanese mathematicians 21st-century Japanese mathematicians Fellows of the American Mathematical Society Functional analysts Academic staff of Waseda University University of Pennsylvania faculty