Efim Zelmanov — math (fields medal) with roots in the USSR
Efim Zelmanov is a Russian-American mathematician who was awarded the Fields Medal in 1994 for his solution to the Restricted Burnside Problem — a major open question in group theory that had stood for decades. He was born in Khabarovsk, USSR, and later emigrated to the United States.
Tracing the roots — Khabarovsk
Born in Khabarovsk in 1955 and educated at Novosibirsk State University and Leningrad State University, Zelmanov is a product of the Soviet mathematical tradition — one of the most powerful intellectual cultures in the 20th century. He emigrated to the US after the Soviet collapse and joined the University of California, San Diego.
Khabarovsk. At the time, this region was one of the fifteen republics of the Soviet Union.