His major contributions are in the theory of quantum integrable systems, separation of variables, special functions.
He graduated from the Department of Physics, Leningrad State University (USSR) in 1978 and earned PhD (Candidate) in 1980 and DrSci (Habilitation) degree in 1989, both at Steklov Mathematical Institute, St. Petersburg.
He then held various research positions at Steklov until 2001, when he moved to the University of York.
[1] He provided, via particular examples, ideas that led to the discovery of quantum groups and Yangians.
[3] He developed the method of separation of variables in the theory of integrable systems.