Evgenii Nikishin

Evgenii Mikhailovich Nikishin (Евгений Михайлович Никишин, 23 June 1945, Penza Oblast – 17 December 1986) was a Russian mathematician, who specialized in harmonic analysis.

Nikishin earned in 1969 his candidate doctorate at Moscow State University and in 1971 his habilitation (Russian doctorate) at the Steklov Institute under Pyotr Ulyanov (1928–2006). In 1977 he became a professor at Moscow State University, where he remained until his death after a long illness.

He worked on approximation theory, especially Padé approximants. Nikishin systems of functions are named after him. Also named in his honour is the Nikishin-Stein factorisation theorem, which is a 1970 generalization by Nikishin of the Stein factorisation theorem. Nikishin also did research on rational approximations in number theory and wrote a monograph on such approximations in a unified approach that also treated rational approximations in function spaces.

In 1972 he won the Lenin Komsomol Prize and in 1973 he won the Salem Prize. In 1978 he was an Invited Speaker (The Padé Approximants) at the International Congress of Mathematicians in Helsinki.

• "Resonance theorems and super linear operators". Russian Mathematical Surveys. 25 (6): 125–187. 1970. doi:10.1070/rm1970v025n06abeh001270. 
• with Vladimir Nikolaevich Sorokin: Rational approximations and orthogonality. AMS. 1991.