Sergey Mergelyan

Sergey Nikitovich Mergelyan (1928 to 2008) was a Soviet and Armenian mathematician who made major contributions to approximation theory. Born in Simferopol to Armenian parents, he grew up in Yerevan, graduated from Yerevan University in 1947 and took his doctorate at the Steklov Institute of Mathematics in 1949 at the age of twenty, the youngest Doctor of Sciences in Soviet history. In 1951 he formulated and proved Mergelyan's theorem on uniform polynomial approximation of functions of a complex variable, which settled a classical problem begun in 1885 and built on results of Weierstrass, Runge, Walsh, Lavrentyev and Keldysh. He became a corresponding member of the Academy of Sciences of the Soviet Union at twenty-four, won the Stalin Prize in 1952 and was a pioneer of Soviet computational mathematics. He worked at Yerevan University, Moscow State University and the Steklov Institute.