Professor Yuri Kagan, outstanding theorist in physics, passed recently away. He was a student of Prof. L.D. Landau and the natural talent of Yu. Kagan was shortly noticed by Academicians I.K. Kikoin and A.P. Aleksandrov. Prof. Kagan gave rise to unique scientific school whose members are currently working successfully in the world's leading centres. The scientific interests of Prof. Kagan cover a wide range of physical phenomena in such fields of physics as molecular physics, condensed matter theory, quantum and classical kinetics, the theory of interaction of nuclear radiation and charged particles with the substance. The results of the Kagan's research in these fields of physics are published in a series of his brilliant papers in the journals as JETP Letters, JETP and Physics-Uspekhi and remain actual so far.

His students, many of them being the world-wide recognised scientists, continue the research in these fields of physics. Prof. Kagan, brilliant lecturer, was delivering the lecture course on the modern theory of solid state physics at the Moscow Engineering Physics Institute, his Alma Mater, for more than 40 years. His lecture course was a starting point not only for the future theorists in physics but also for many experimentalists, and Prof. Kagan was always ready to discuss their researches in physics. Prof. Kagan was the member of many prestigious scientific academies and physical societies, and honorary Professor of many Universities in the world. On the other side he was uncommonly approachable both for the eminent scientists and for the research beginners.

After Kagan's decease there have remained his remarkable scientific results, numerous students, numerous former students, successors, thankful readers, and the blessed memory of him.