Gregori Margulis
See also: Margulis
Gregori Aleksandrovich Margulis (born the February 24th 1946) is a Russian Mathématicien known for its work of great scale on the discrete sub-groups of the groups of Dregs, and the introduction of methods coming from the ergodic Théorie in Approximation diophantienne.
It received the Médaille Fields in 1978, but it had then not been able to go to Helsinki to receive its price in person, the Soviet authorities having prohibited to him to go there. It also received the Prix Wolf in 2005, joining only six other mathematicians to have received these two prices.
It was born in an Jewish family from Moscow, then in Soviet Union. After having studied with the University of State of Moscow, it began its research in ergodic theory. Its first work with David Kazhdan gave places to the Théorème of Kazhdan-Margulis, a result on the discrete groups. Its Théorème of superrigidity formulated in 1975 clarified many traditional conjectures about the characterization of the arithmetic groups among the network X of the groups of Dregs.
In 1986, Margulis completely showed the Conjecture of Oppenheim about the quadratic forms and the approximation diophantienne. This conjecture had remained open nearly one half-century, during which considerable progresses had been made, in particular thanks to the Méthode of the circle of Hardy-Littlewood, but the use of the methods resulting from the Théorie of the groups was decisive. He then formulated a new research program according to the same direction, including the Conjecture of Littlewood, which had an unquestionable influence.
He occupies since 1991 a pulpit at the university of Yale.