He is a professor of mathematics at Princeton University, specializing in complex analysis, who introduced indigenous bundles.

[1] For his graduate studies he went to Princeton University, where he earned his Ph.D in 1955 under Salomon Bochner with thesis A classification of factors of automorphy.

He was a visiting professor in São Paulo in 1958, Cambridge in 1959/60, Munich in 1967, Oxford in 1968, Boulder in 1970, and Los Angeles in 1972.

In 1970 he was an invited speaker at the International Mathematical Congress in Nice (Some multivariable problems arising from Riemann surfaces).

Among his doctoral students are Sheldon Katz, Henry Laufer, Richard S. Hamilton, Yum-Tong Siu, and Michael Eastwood.