Kiyoshi Itō

was a Japanese mathematician who made fundamental contributions to probability theory, in particular, the theory of stochastic processes. He invented the concept of stochastic integral and stochastic differential equation, and is known as the founder of so-called Itô calculus. He also pioneered the connections between stochastic calculus and differential geometry, known as stochastic differential geometry. He was invited for the International Congress of Mathematicians in Stockholm in 1962. So much were Itô's results useful to financial mathematics that he was sometimes called "the most famous Japanese in Wall Street".

Fellow mathematician Daniel W. Stroock noted that "People all over realized that what Ito had done explained things that were unexplainable before." He excelled in his studies as a youth.

After this period he continued to develop his ideas on stochastic analysis with many important papers on the topic. In 1952, he became a professor at the University of Kyoto. This was his longest stint outside Japan. Among the courses he taught at Cornell was one in Higher Calculus.

Itô wrote not only in Japanese but also in Chinese, German, French and English.

When Itô left Cornell and returned to the University of Kyoto, he served as director of their Research Institute for Mathematical Sciences. Later, IMU President Sir John Macleod Ball personally presented the medal to Itô at a special ceremony held in Kyoto. In October 2008, Itô was honored with Japan's Order of Culture, and an awards ceremony for the Order of Culture was held at the Imperial Palace.

Itô died on November 10, 2008, in Kyoto, Japan, at age 93, of respiratory failure.

Selected publications