Hans Lewy

Hans Lewy (1904 to 1988) was a Polish-born American mathematician who worked on partial differential equations and on functions of several complex variables. Born in Breslau, he studied at Göttingen, where Richard Courant supervised his research and he took his doctorate in 1926. In 1928 he wrote with Courant and Friedrichs a paper on the partial differential equations of mathematical physics that gave criteria for the stability of numerical solutions, work that grew more important once computers arrived. After Hitler came to power in 1933 he emigrated to the United States, spent two years at Brown University and from 1935 taught at the University of California at Berkeley, where he became a full professor in 1945. His 1957 paper gave a simple smooth linear partial differential equation that has no solution, a result that had a large effect on the field. He received the Steele Prize of the American Mathematical Society in 1979 and shared the Wolf Foundation prize with Kodaira in 1986, and in 1950 he was dismissed with others for refusing a loyalty oath, later being reinstated by the courts.