Nikolai Nikolaevich Luzin, Russian: Никола́й Никола́евич Лу́зин (December 9, 1883, Irkutsk – January 28, 1950, Moscow), was a Soviet/Russian mathematician. He was noted for his work in descriptive set theory and aspects of mathematical analysis with strong connections to point-set topology. He was the eponym of Luzitania, a loose grouping of young Moscow mathematicians in the first half of the 1920s. They adopted his set-theoretic orientation, and went on to apply it in other areas of mathematics.
He started studying mathematics in 1901 at Moscow University, where his advisor was Dimitri Egorov. From 1910 to 1914 he studied at Göttingen, where he was influenced by Edmund Landau. He then resurned to Moscow and received Ph.D. in 1915. During Russian Civil War (1918 – 1920) Luzin left Moscow for the Polytechnical Institute Ivanovo-Voznesensk (now called Ivanovo State University of Chemistry and Technology). He returned to Moscow in 1920.
In the 1920s Luzin organized a famous research seminar at Moscow University. His doctoral students included some of the most famous Soviet mathematicians: Pavel Aleksandrov, Nina Bari, Aleksandr Khinchin, Andrey Kolmogorov, Alexander Kronrod, Mikhail Lavrentyev, Lazar Lyusternik, Pyotr Novikov, Lev Schnirelmann, and Pavel Urysohn.
In July-August 1936 Luzin was criticised in Pravda in a series of articles. It was alleged that he published "would-be scientific papers," "felt no shame in declaring the discoveries of his students to be his own achievements," stood close to the ideology of the "black hundred", orthodoxy, and monarchy "fascist-type modernized but slightly." Luzin was claimed at a special trial of a Commission of the Academy of Sciences of the USSR which endorsed all accusitions of Luzin as an enemy under the mask of a Soviet citizen. The method of political insinuations and slander was used against the old Muscovite professorship many years before the article in Pravda. The declaration of November 21, 1930 of the "initiative group" of the Moscow Mathematical Society which consisted of L. A. Lyusternik, L. G. Shnirelman, A. O. Gelfond , and L. S. Pontryagin claimed that "there appeared active counter-revolutionaries among mathematicians." Some of these were pointed out, namely, D. F. Egorov who had been arrested shortly before the declaration.
The political offensive against Luzin was launched by not only Stalin's repressive ideological authorities but also a group of Luzin's students headed by Pavel Alexandrov. Althought the Commission convicted Luzin, he was not expelled from the Academy nor arrested, presumably due to an oral direction of Stalin. However, he was never rehabilitated even after the death of Stalin. His students, participating in his political execution, never showed any remorse. The Luzin case was a prologue to the years of Stalin's repressions and political attacks on genetics, relativity, and other trains of free scientific thought.