born March 26, 1913, Budapest, Hung. died Sept. 20, 1996, Warsaw, Pol. Hungarian mathematician. He proved a classic theorem of number theory (1933), founded the study of probabilistic number theory with Aurel Wintner and Mark Kac, proved important results in approximation theory with Paul Turan, and with Atle Selberg gave an astounding elementary proof of the prime number theorem (1949). Famously eccentric, he traveled almost constantly for his last 40 years, collaborating with hundreds of mathematicians on numerous problems