Gregori Aleksandrovich Margulis (Russian: ?????´??? ??????´??????? ?????´???, first name often given as Gregory, Grigori or Grigory; born February 24, 1946) is a Russian-American mathematician 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.