"American mathematician" . "Sergiu Klainerman (born May 13, 1950) is a mathematician known for his contributions to the study of hyperbolic differential equations and general relativity. He is a Professor in the Department of Mathematics at Princeton University, a position he held since 1987. From 1980 to 1987 he was a faculty member at New York University.Klainerman is a member of the U.S."@en . . . "Sergiu Klainerman"@en . . "1950Z"^^ . "1950-05-13Z"^^ . . . . . . . "Klainerman, Sergiu"@en .