Celebratio Mathematica

Irving Kaplansky

Irving Kaplansky
retired professor of mathematics, 1917–2006

from University of Chicago News Office

Irving Ka­plansky, a re­tired Pro­fess­or of Math­em­at­ics at the Uni­versity of Chica­go and a lead­ing au­thor­ity on al­gebra, died Sunday, June 25 at home in Sher­man Oaks, Cal­if. He was 89.

Ka­plansky loved work­ing with young people, and he served as Ph.D. ad­visor to 55 gradu­ate stu­dents, the most of any math­em­at­ics pro­fess­or ever to have taught at the Uni­versity of Chica­go, said J. Peter May, Pro­fess­or of Math­em­at­ics at the Uni­versity.

“He pub­lished close to 150 pa­pers, the earli­est ap­pear­ing in 1939 and the last in 2003, an as­ton­ish­ing span of activ­ity for a math­em­atician,” May said. “Ka­plansky had a great sense of hu­mor, or per­haps more ac­cur­ately fun. He en­joyed life and lit up any room he was in. He liked quirky math­em­at­ic­al prob­lems with a real life twist. For ex­ample, a 1943 pa­per gave an el­eg­ant solu­tion of the prob­lem of find­ing the num­ber of ways that a giv­en num­ber of mar­ried couples may be seated at a round table, men al­tern­at­ing with wo­men, so that no wife sits next to her own hus­band.”

Ka­plansky re­ceived the pres­ti­gi­ous Steele Prize in 1989 from the Amer­ic­an Math­em­at­ic­al So­ci­ety for his ca­reer-long in­flu­ence on math­em­at­ics. The cita­tion said he re­ceived the hon­or “for his last­ing im­pact on math­em­at­ics, par­tic­u­larly math­em­at­ics in Amer­ica. By his en­er­get­ic ex­ample, his en­thu­si­ast­ic ex­pos­i­tion and his over­all gen­er­os­ity, he has made strik­ing changes in math­em­at­ics and has in­spired gen­er­a­tions of young­er math­em­aticians.”

His re­search was de­voted primar­ily to al­gebra and func­tion­al ana­lys­is. He con­trib­uted many ba­sic res­ults on the struc­ture of Banach al­geb­ras, on loc­ally com­pact groups and on group rep­res­ent­a­tions.

He also did fun­da­ment­al work on ring the­ory and wrote im­port­ant books, among them, Com­mut­at­ive Rings (1970), In­fin­ite Abeli­an Groups (1969) and Lie Al­geb­ras and Loc­ally Com­pact Groups (1971).

From 1957 to 1961, he was ed­it­or of the Pro­ceed­ings of the Amer­ic­an Math­em­at­ic­al So­ci­ety.

In 1965, he was elec­ted to the Amer­ic­an Academy of Arts and Sci­ences. He was elec­ted to the Na­tion­al Academy of Sci­ences in 1966. He was Chair­man of the Board of Trust­ees of the Amer­ic­an Math­em­at­ic­al So­ci­ety in 1971 and Pres­id­ent from 1985–86.

Ka­plansky, a nat­ive of Toronto, Canada, re­ceived a B.A. in 1938 and an M.A. in 1939 from the Uni­versity of Toronto. He re­ceived a Ph.D. in 1941 from Har­vard. At the Uni­versity of Toronto as an un­der­gradu­ate, he was on the win­ning team of the first Wil­li­am Low­ell Put­nam com­pet­i­tion, a math­em­at­ic­al con­test for stu­dents from the US and Canada.

After hold­ing teach­ing po­s­i­tions at Har­vard and Columbia, he joined the fac­ulty of the Uni­versity of Chica­go in 1945 and was made Pro­fess­or in 1956. He served from 1962 to 1967 as Chair­man of Math­em­at­ics. In 1969, he was ap­poin­ted the George Her­bert Mead Dis­tin­guished Ser­vice Pro­fess­or.

Ka­plansky re­ceived the Uni­versity’s Quan­trell Award for Ex­cel­lence in Un­der­gradu­ate Teach­ing in 1961. The cita­tion read, “Stu­dents at the Uni­versity have al­ways found his treat­ment of math­em­at­ics ori­gin­al and il­lu­min­at­ing to an ex­traordin­ary de­gree, and his teach­ing at once thor­ough, vivid and in­spir­ing.”

In 1984 he be­came Dir­ect­or of the Math­em­at­ic­al Sci­ences Re­search In­sti­tute in Berke­ley, Cali­for­nia, a post he held un­til 1992.

Dav­id Eis­en­bud, cur­rent Dir­ect­or of MSRI and a former stu­dent said, “I re­mem­ber well his highly en­ter­tain­ing and beau­ti­fully pol­ished lec­tures from my stu­dent days in Chica­go. Whatever he taught, I signed up for the course, it was such a pleas­ure to listen to him.

“After step­ping down as MSRI dir­ect­or, at 80, Ka­plansky went back to full-time re­search math­em­at­ics, and re­turned to num­ber the­ory, one of his first loves,” Eis­en­bud said.

As an avid mu­si­cian and pi­an­ist, Ka­plansky played in or dir­ec­ted many Uni­versity mu­sic­al and theat­er pro­duc­tions, in­clud­ing its an­nu­al pro­duc­tions of the works of Gil­bert and Sul­li­van.

Ka­plansky is sur­vived by his wife of 55 years, Chel­lie, two sons, Steven, of Sher­man Oaks, CA and Alex of Hills­bor­ough, NJ, a daugh­ter, Lucy, of New York City, a sing­er, and two grand­chil­dren.