Sergiu Klainerman is a mathematician who has made contributions to our understanding of nonlinear partial differential equations.
His main body of work is directed to the study of nonlinear wave equations where he helped develop new techniques to establish the first results on global existence for large classes of such equations. Klainerman’s work, done in collaboration with MacArthur Fellow Demetrios Christodoulou, has led to the first general global existence result in general relativity. Their finding establishes a rigorous theory of gravitational radiation at large distances from astronomic sources. He has also done work, in collaboration with Andrew Majda, on the breakdown of solutions to the equation of a vibrating string and on problems concerning the zero Mach number limit of compressible flow.
Klainerman is a professor of mathematics at Princeton University, where he has been a member of the faculty since 1987. He served previously as a professor of mathematics at New York University (1980-1987) and as a Miller Instructor at the University of California at Berkeley (1978-1980).
Klainerman received a Diploma de Licenta (1973) from the University of Bucharest and a Ph.D. (1978) from New York University.