1914-1993

Russian-American mathematician known for his work on Teichmuller theory, pseudoanalytic functions, quasiconformal mappings, and Kleinnian groups. He studied in Russia and Switzerland and received his Ph.D. from Charles University in Prague, Czechoslovakia, before escaping World War II by coming to the United States in 1940. He conducted research for Brown University on the two-dimensional subsonic fluid flow for the United States war effort. He held teaching posts at Princeton, Courant Institute, and Columbia University, where he remained until he retired.