Gian-Carlo Rota (April 27, 1932 – April 18, 1999, known as Juan Carlos Rota to Spanish speakers) was an Italian-born American mathematician and philosopher.
He was born in Vigevano, Italy, where he lived until he was 13 years old. At that time his family fled Italy because his father, Giovanni Rota, was likely to be an object of fascist persecution.
He attended the Colegio Americano de Quito in Ecuador, and earned degrees at Princeton University and Yale University. For most of his career he was a professor at the Massachusetts Institute of Technology, where he was the only person ever to be appointed Professor of Applied Mathematics and Philosophy. He was also the Norbert Wiener Professor of Applied Mathematics. (See also Norbert Wiener.)
From 1966 until his death he was a consultant at Los Alamos National Laboratory, frequently visiting to lecture, discuss, and collaborate, notably with his friend Stan Ulam.
He began his career as a functional analyst, but changed directions and became a distinguished combinatorialist. His series of ten papers on "Foundations of Combinatorics" in the 1960s is credited with making it a respectable branch of modern mathematics. He said that the one combinatorial idea he would like to be remembered for is the correspondence between combinatorial problems and problems of the location of the zeroes of polynomials. He worked on the theory of incidence algebras (which generalize the 19th-century theory of Möbius inversion) and popularized their study among combinatorialists, set the umbral calculus on a rigorous foundation, unified the theory of Sheffer sequences and polynomial sequences of binomial type, and worked on fundamental problems in probability theory. His philosophical work was largely in the phenomenology of Edmund Husserl.
He died in Cambridge, Massachusetts.