Grigori Margulis

Grigory Margulis
Grigory Margulis
Born	(1946-02-24) February 24, 1946 (age 71) Moscow, Soviet Union
Nationality	Russian, American
Fields	Mathematics
Institutions	Yale University
Alma mater	Moscow State University
Doctoral advisor	Yakov Sinai
Doctoral students	Emmanuel Breuillard Hee Oh
Known for	Diophantine approximation Lie groups Superrigidity theorem Arithmeticity theorem Expander graphs Oppenheim conjecture
Notable awards	Fields Medal (1978) Lobachevsky Prize (1996) Wolf Prize (2005)

Gregori Aleksandrovich Margulis (Russian: Григо́рий Алекса́ндрович Маргу́лис, first name often given as Gregory, Grigori or Grigory; born February 24, 1946) is a Russian-Americanmathematician known for his work on lattices in Lie groups, and the introduction of methods from ergodic theory into diophantine approximation. He was awarded a Fields Medal in 1978 and a Wolf Prize in Mathematics in 2005, becoming the seventh mathematician to receive both prizes. In 1991, he joined the faculty of Yale University, where he is currently the Erastus L. DeForest Professor of Mathematics.

Margulis was born in Moscow, Soviet Union. He received his PhD in 1970 from the Moscow State University, starting research in ergodic theory under the supervision of Yakov Sinai. Early work with David Kazhdan produced the Kazhdan–Margulis theorem, a basic result on discrete groups. His superrigidity theorem from 1975 clarified an area of classical conjectures about the characterisation of arithmetic groups amongst lattices in Lie groups.

He was awarded the Fields Medal in 1978, but was not permitted to travel to Helsinki to accept it in person. His position improved, and in 1979 he visited Bonn, and was later able to travel freely, though he still worked in the Institute of Problems of Information Transmission, a research institute rather than a university. In 1991, Margulis accepted a professorial position at Yale University.