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.
Sergey Stechkin Sergey Borisovich Stechkin (Russian: Серге́й Бори́сович Сте́чкин ) (6 September 1920 – 22 November 1995) was a prominent Soviet mathematician who worked in theory of functions (especially in approximation theory) and number theory.