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. He then went to the
University of Pennsylvania, where he became a professor in 1966 and remained until 1979. He then returned to Japan and went to the
Nihon University. In 1992, he received the
Japanese Mathematical Society Autumn Prize. He is a fellow of the
American Mathematical Society. Sakai's main field is
functional analysis and
mathematical physics. 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.) == Works ==