Jean Leray

Jean Leray was a French mathematician who worked on both partial differential equations and algebraic topology, born in Chantenay-sur-Loire, now part of Nantes, on 7 November 1906. He studied at the Ecole Normale Superieure from 1926 to 1929 and received his Ph.D. in 1933. In 1934 he published an important paper founding the study of weak solutions of the Navier-Stokes equations and, with Juliusz Schauder, discovered the topological invariant now called the Leray-Schauder degree. From 1938 to 1939 he was professor at the University of Nancy. His main work in topology was carried out while he was a prisoner of war in a camp in Edelbach, Austria, from 1940 to 1945, where he concealed his expertise on differential equations to avoid aiding the German war effort, and this work proved seminal for spectral sequences. He was elected to the American Academy of Arts and Sciences and the American Philosophical Society in 1959 and the United States National Academy of Sciences in 1965, and received the Wolf Prize in Mathematics in 1979. He died on 10 November 1998.