Ennio De Giorgi

Ennio De Giorgi was an Italian mathematician who worked on partial differential equations and the foundations of mathematics, born on 8 February 1928. His first work was in geometric measure theory, on sets of finite perimeter which he called in 1958 Caccioppoli sets after his mentor and friend, and it brought him immediate recognition. In 1969, with Enrico Bombieri and Enrico Giusti, he solved the Bernstein problem about minimal surfaces in 8 dimensions, for which Bombieri won the Fields Medal in 1974. His regularity theory for minimal hypersurfaces changed how the theory of minimal surfaces and the calculus of variations are viewed. His honours include the Caccioppoli Prize in 1960, the National Prize of the Accademia dei Lincei in 1973, the Wolf Prize in 1990 and honorary degrees from the University of Paris in 1983 and the University of Lecce in 1992, and he was elected to many academies including the Accademia dei Lincei and the National Academy of Sciences of the United States. He died on 25 October 1996.