Obituary [Vladimir Sergeevitch Buldyrev]

Summary form only given, as follows. Vladimir Sergeevitch Buldyrev, whose role was essential in transforming the diffraction theory into an important force of mathematical physics in the second half of the 20th century, died on 5 April 2010, after a two-month illness. His 80th birthday we celebrated at "Diffraction Days 2009." Vladimir Sergeevitch was a Professor in the Department of Higher Mathematics and Mathematical Physics, Faculty of Physics of the St. Petersburg State University, where his teaching career lasted for more than 60 years. He was the key figure in sustaining the department as a center for research and the training of several generations of mathematical physicists who were to go on to pursue successful research and teaching careers. It must be added that the initiation of the "Diffraction Days" conferences is undeniably connected with his name. Vladimir Sergeevitch was the author and coauthor of many pioneering works in the field of the mathematical theory of diffraction. His studies of the \´whispering gallery\´ and \´jumping ball\´ modes had resulted in proposing the so-called \´infinitesimal ray method\´ and the technique of investigation of the ray stability based on the first approximation. Along with the boundary layer approach originated by V.A. Fock, these techniques opened a new era in the diffraction theory lasting up to the present. More than twenty students got their PhD degree under Buldyrev\´s supervision; six of them became professors later on. He wrote four monographs and textbooks, the best known of which is "Asymptotic Methods in Short Wave Diffraction Problems" co-authored with V.M. Babich and translated into English. The State Prize of the USSR and the St. Petersburg University Prize are among of his awards.