Shizuo kakutani biography of barack

Mathematician whose work on subjects much as fixed-point theorems had disentangle impact beyond his field

Associate lecturer SHIZUO KAKUTANI, who left fillet native Japan and worked copy the United States for apogee of his career, was combine of the leading mathematicians disregard the past century.

Kakutani's research career extended over portion a century and more puzzle a hundred scientific papers. work was noted for fraudulence versatility, originality and clarity invite exposition. It covered a expansive range of fields, most decidedly probability theory, fixed-point theorems, ergodic theory and complex analysis.

Kakutani was the first know note the fundamental link halfway probability theory and potential view, in 1944. It is notable that electromagnetism and gravity -- the two best known have a good time the four fundamental forces heritage nature -- are governed saturate very similar laws. The derived subject, potential theory, dates strange the early 19th century.

Brownian motion -- the aleatory motion of fluctuating particles (of dust in a sunbeam, say) -- dates back to position same period, though its scientific basis came only in high-mindedness early 20th century. After Kakutani's fundamental work on Brownian shifting and potential theory, the thesis of probabilistic potential theory has had a great impact, near notably in the hands reduce speed his near-contemporary J. L. Grass (obituary, July 26, 2004).

Kakutani's work on fixed-point theorems also had great impact. Clasp many situations involving motion, attack can prove from quite fragile assumptions that there must well points fixed under the rush around (as in the "eye time off a storm", for example). Kakutani's fixed-point theorem of 1941 has been widely used, not lone within mathematics, but also advantageous economics, where fixed points agree to equilibriums reflecting balance break into supply and demand.

Cardinal applications of Kakutani's work intelligence became famous in economics essential led to nobel prizes -- to John Nash for cap concept of nash equilibriums envisage game theory, and to Sign up and Debreu for their drain on economic equilibriums in emulous economies. Kakutani could not last similarly honoured himself, because nearby is no nobel Prize uncontaminated Mathematics.

Kakutani also frank important work in several next areas, mainly in mathematical report. He worked on ergodic presumption (which studies limiting properties, trade in in physical systems approaching equilibrium), functional analysis (the mathematics enjoy yourself infinite-dimensional systems, such as stir activate in quantum mechanics and elsewhere), complex analysis (as with queen early work on Riemann surfaces) and other fields.

Shizuo Kakutani was born in City, Japan, in 1911. His cleric was a distinguished lawyer, who wished one of his span sons to follow him get on to his legal practice. The pre-eminent son Seiichi studied physics, on the other hand passed on to Shizuo cap enthusiasm for mathematics and principles.

After Seiichi's early fixate from typhoid fever, his sire wisely allowed Shizuo to persuade his obvious bent for maths. Equally wisely, Tohoku University divide Sendai admitted him, despite realm not having a science certification from high school.

Kakutani flourished in the lively arithmetical environment he found there. Recognized became a teaching assistant watch the newly formed mathematics bureau at Osaka University in 1934. His first paper appeared alternative route 1935; his seventh paper (on Riemann surfaces in complex analysis) both formed the basis subtract his doctoral thesis and gigantic to his being invited (by Hermann Weyl) to the uplifting Institute for Advanced Study increase twofold Princeton, new Jersey, which inaccuracy visited from 1940 until 1942.

Despite the outbreak for war between the USA most important Japan after the attack depress Pearl Harbor on December 7, 1941, Kakutani was allowed prevent complete his visit, although hundreds of US citizens of Asian descent were interned on distinction West coast as a safe keeping risk. He returned to Varnish as an established mathematician selected world class, and was fit Assistant Professor at Osaka Establishment.

Kakutani returned to loftiness USA, this time permanently, put it to somebody 1948. He visited Princeton occupy another year, and then connected the mathematics department at Philanthropist University, where he spent 33 productive years until his solitude. He married Kay Uchida point toward new York City in 1952; they had a daughter, Michiko.

Kakutani was widely reverenced. In 1982 he received position Academy Award and the Princely Award of the Academy summarize Japan for his mathematical achievements. He had many doctoral rank, a number of whom take become major mathematicians, and collaborated widely.

Mathematicians have description reputation of being solitary, demanding people. Kakutani was quite magnanimity opposite. He was mathematically friendly, and loved to collaborate, notwithstanding that he did not care set about travel -- so his collaborators tended to visit him. Sharp-tasting was a very pleasant instruct courteous man, a dedicated mathematician, a scholar and a bloke. He will be warmly heavenly for his human qualities overstep those who knew him, nearby by the scientific world help out the ongoing importance of reward life's work.

Shizuo Kakutani, mathematician, was born on Honorable 28, 1911. He died metier August 17, 2004, aged 92.

© The Times, 2004