Which Russian mathmatician contributed to number theory, Grigori Perelman or Ivan Fesenko?
Grigori Perelman Grigori Yakovlevich Perelman (Russian: Григо́рий Я́ковлевич Перельма́н ; ] ; born 13 June 1966) is a Russian mathematician. He made a contribution to Riemannian geometry and geometric topology.
Yevgeny Svetlanov Yevgeny Fyodorovich Svetlanov (Russian: Евгéний Фёдорович Светлáнов ; 6 September 1928—3 May 2002) was a Russian conductor, composer and, though less well known for it, a pianist.