Which Russian mathmatician contributed to number theory, Grigori Perelman or Ivan Fesenko?
Ivan Fesenko Ivan Fesenko (Russian: Иван Борисович Фесенко ; born 1962) is a mathematician working in number theory and other areas of modern mathematics.
Grothendieck's Galois theory In mathematics, Grothendieck's Galois theory is a highly abstract approach to the Galois theory of fields, developed around 1960 to provide a way to study the fundamental group of algebraic topology in the setting of algebraic geometry. It provides, in the classical setting of field theory, an alternative perspective to that of Emil Artin based on linear algebra, which became standard from about the 1930s.