Albert Muchnik

Albert Abramovich Muchnik was a Russian mathematician, born on 2 January 1934, who worked in the field of foundations and mathematical logic. He received his Ph.D. from Moscow State Pedagogical Institute in 1959 under Pyotr Novikov, with a dissertation titled Solution to the Post Reducibility Problem. His 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, a result now known as the Friedberg-Muchnik theorem. In 1963 he introduced a generalisation of Turing degrees called Muchnik degrees, and he proved that the lattice of Muchnik degrees is Brouwerian. He died in February 2019.