Sergei Viktorovich Bochkarev

The prominent Soviet and Russian mathematician, expert in the theory of functions and functional analysis Sergei Viktorovich Bochkarev passed away on 8 June 2021. In less than a month he would have celebrated his 80th birthday. In this article we expound on the main results of his research and recall the key milestones of his journey through life. He was born in Kuibyshev (now Samara) on 24 July 1941. His father Viktor Aleksanrdrovich Bochkarev, born in Saratov, was a well-known expert in literature, professor, Doctor of Science (philology), who had long been Head of the Department of Russian and Foreign Literature at Kuibyshev State Pedagogical Institute. His mother Tat’yana Georgievna Demina was an engineer and taught at the Kuibyshev Construction School. In 1958, having graduated from High School no. 94 in Kuibyshev with a gold medal, Bochkarev enrolled at the Moscow Institute of Physics and Technology. In 1964–1967 he pursued postgraduate studies at the Department of Higher Mathematics of the Institute, where P. L. Ul’yanov was his research advisor. In 1969 he defended his Ph.D. thesis at the Steklov Mathematical Institute of the USSR Academy of Sciences. His first job was at the Central Institute for Economics and Mathematics of the USSR Academy of Sciences, where he stayed for three years. From April 1971 until the end of his life, for slightly more than 50 years, Sergei Bochkarev worked at the Department of the Theory of Functions of the Steklov Mathematical Institute and focused exclusively on research. In 1974 he defended his D.Sc. thesis on Function classes and Fourier coefficients with respect to complete orthonormal systems. Bochkarev’s list of publications1 contains more than 70 titles. We only mention his achievements that are the most important ones in our opinion and have earned him the unchallenged reputation as ‘solver of fundamental problems’ among experts in analysis. The first large cycle of Bochkarev’s papers, which made up his doctoral dissertation, was devoted to the properties of the Fourier coefficients of functions in various function spaces with respect to classical or general orthonormal systems. By the