Yu. V. Novozhilov: Creative path

Abstract

The scientific activity of Yu. V. Novozhilov started under the influence of two outstanding physicists of that time: Corresponding Member of the Academy Ya. I. Frenkel and Academician V. A. Fock. From these two leading scientists, so different from each other, Novozhilov inherited a devotion to science, a taste for research at the frontier, a true understanding of the relevance of the studied questions, and a rigorous mathematical approach combined with physical intuition. The initial stage of Novozhilov’s scientific work coincided with the period of explosive development of quantum field theory and the theory of elementary particles in the 1940s and 1950s, with the creation of renormalization theory and relativistic scattering theory. The plenitude of new ideas and methods and the extremely rapid pace of research characteristic of that period determined Novozhilov’s direction and style of work. At this time, Novozhilov published papers on the functional method in quantum field theory. In them, he developed the theory of renormalization in the framework of Fock’s functional method and studied the problem of the variation of functionals in Fermi fields. The keen interest of Novozhilov in the functional method was somewhat ahead of its time: later, in the 1970s, this method became the base for analyzing gauge fields, which underlie the modern theory of fundamental interactions. The review paper “Functional method in quantum field theory” [1] by Novozhilov and A. V. Tulub, published as a separate book in the USA, was long the only handbook on the functional method and is still relevant today. In 1953, Novozhilov was awarded a first-degree university prize for the paper “Application of Fock’s functional method to the problem of self-energy” [2]. We briefly discuss this first paper by Novozhilov. In the abstract, he wrote: “Fock’s functional method is used to obtain the Dirac equation with electromagnetic mass and radiative corrections.” In the functional method, a state is described by an analytic functional Ω{α(x)} of the complex function α(x). The creation and annihilation operators a † (x )a nda(x) correspond to multiplication by α(x )a nd the functional derivative of that function. In application to the Dirac equation in quantum electrodynamics, we start from the equation for the state functional [ ˆ