How Young We Were

Abstract

I met Kostya in 1971 in the Steklov Institute of Mathematics. Those days he was a graduate student and I was an undergraduate student of Professor Sergei Aleksandrovich Telyakovskii. Later, we both defended our PhD dissertations under Telyakovskii’s auspices. Thus, we are “scientific brothers” with Kostya. In the beginning of the 1970s trigonometric series and approximation of periodic functions by trigonometric polynomials was a “hot topic.” The Russian translation of the fundamental book of A. Zygmund on trigonometric series was published in 1965. This and strong traditions of Russian school in the theory of functions and in approximation theory attracted many young mathematicians including Kostya and me to that topic. These activities were concentrated around seminars run by D.E. Men’shov and P.L. Ul’yanov in Moscow State University and by S.B. Stechkin in the Steklov Institute of Mathematics. We had a chance to interact on an everyday basis not only between ourselves but also with great mathematicians working in that area. Let me discuss in detail only one of Kostya’s results from [2]which will help to understand a wonderful mathematical atmosphere in Moscow of those days.