Albert Muchnik
Albert Abramovich Muchnik is a Russian mathematician who worked in the field of foundations and mathematical logic.
He received his Ph.D. from Moscow State Pedagogical Institute in 1959 under the advisorship of Pyotr Novikov. Muchnik's most significant contribution was on the subject of relative computability. He and Richard Friedberg independently introduced the priority method which gave an affirmative answer to Post's Problem regarding the existence of recursively enumerable Turing degrees between 0 and 0' . This result, now known as the Friedberg-Muchnik Theorem, opened study of the Turing degrees of the recursively enumerable sets which turned out to possess a very complicated and non-trivial structure. He also has a significant contribution in the subject of mass problems where he introduced the generalisation of Turing degrees, called "Muchnik degrees" in his work On Strong and Weak Reducibilities of Algorithmic Problems published in 1963. Muchnik also elaborated Kolmogorov's proposal of viewing intuitionism as "calculus of problems" and proved that the lattice of Muchnik degrees is Brouwerian.
Muchnik was married to the Russian mathematician Nadezhda Ermolaeva. Their son Andrej, who died in 2007, was also a mathematician working in foundations of mathematics. He died in February 2019.Selected publications
