Dmitrij Vasilievich Volkov
(July 3, 1925 - January 5, 1996)
Dmitrij V. Volkov initiated and made an outstanding contribution into the development of a number of new fundamental trends in theoretical physics of elementary particles and quantum field theory. In particular, his name is associated with the discovery of supersymmetry and supergravity which are now considered as building blocks of the unified quantum theory of fundamental particle interactions.
D.V. Volkov was born on July 3, 1925 in Leningrad. In 1943 he was recruited into the Red Army as a private and participated in battles of World War II in Karelia and Far East, where he was seriously wounded. In 1946, at the end of the war against Japan, he was discharged from the military duty. He was awarded three medals for military valor.
In 1947 D.V. Volkov entered the Physics Faculty of Leningrad State University, and in 1951, by the order of the Ministry of Higher Education, he was sent along with other best students to study at a newly opened Nuclear Physics Division at the Physics and Mathematics Department of Kharkov State University which he graduated in 1952. In 1956, after having completed his post-graduate studies, he started to work at the Kharkov Institute of Physics and Technology where he spent nearly 40 years of his career from Junior Research Associate to Academician.
In the Fifties the physics of elementary particles underwent an extensive development. So upon having accomplished his Candidate-of-Sciences thesis (PhD) on scalar electrodynamics D.V. Volkov embarked upon research on fundamental problems of elementary particles and quantum field theory. At that time he studied spin-statistics correspondence and established a connection between the Pauli theorem and the CPT-symmetry of commutation relations. In 1959 he proposed a new type of quantum statistics, so called parastatistics or Green-Volkov statistics, which generalized Bose-Einstein and Fermi-Dirac statistics. Parastatistics played an important role in the development of the conjecture about the quark structure of hadrons.
In the beginning of the Sixties, when the Regge theory of poles attracted great deal of attention, D.V. Volkov plunged into the study of the behavior of poles in a relativistic region. In 1962 together with V.N. Gribov he discovered a phenomenon which became known as the "Regge pole conspiracy". The theorem on the "pole conspiracy" established a relation between the poles of scattering amplitudes of relativistic particles with spin and stimulated extensive theoretical and experimental study in high energy physics.
In 1965 D.V. Volkov put forward an important concept of collinear subgroups of symmetries and proposed an effective method of studying particle scattering processes based on the theory of higher symmetry group representations. These and other results obtained by D. V. Volkov in the Sixties constituted his Thesis for the Academic Degree of Doctor of Sciences which he got in 1967.
In the end of the Sixties and the beginning of the Seventies he made an essential contribution into the study of the algebra of currents and spontaneously broken symmetries, and wrote a series of classical papers on the interaction of particles in systems with a degenerate vacuum. D.V. Volkov based this study on a skillful application of group-theoretical methods of E. Cartan, and constructed a general theory of interacting Goldstone particles in field systems with spontaneously broken internal symmetries. When the Veneziano dual model was proposed D.V. Volkov immediately realized that the tachyon problem could be overcome by rebuilding the vacuum state of the model. Using this idea he solved the problem of spontaneous vacuum transition in the Veneziano and Neveu-Schwarz dual model, and established a connection of dual amplitudes and Regge trajectories with internal symmetries and current algebras.
D.V. Volkov also applied the group-theoretical methods for solving problems of statistical and solid state physics. In particular, he realized the idea that magnons can be regarded as Goldstone particles and constructed a generic Lagrangian for spin waves in ordered and disordered magnetic media.
Perhaps, the most instructive fact which reflects an extraordinary way of Volkov's thinking is how he discovered supersymmetry and supergravity, the most important ingredients of modern theory of fundamental interactions. D.V. Volkov again and again returned to a question he asked himself starting the early Sixties on the possibility of the existence of multiplets unifying particles with different spins. The Goldstone theorem gave him an idea to reformulate this question to "Whether fermions can be Goldstone particles?". The affirmative answer came along in 1972 when he (independently from Golfand and Lichtman) introduced supersymmetric transformations mixing bosons and fermions, and considered the first four-dimensional field-theoretical model with spontaneously broken supersymmetry. Supersymmetry has allowed one to nontrivially unify space-time and internal symmetries of elementary particles. A natural problem which D. Volkov addressed to upon the discovery of global supersymmetry was its "localization". This lead to the unification of local supersymmetry transformations with general coordinate transformations of space-time and resulted in the generalization of the theory of gravity to supergravity. D. Volkov was the first who realized that such a generalization requires the graviton to have a fermionic superpartner, a spin 3/2 field called gravitino. In 1973 D.V. Volkov constructed the first supergravity model where the spontaneous supersymmetry breaking lead to the super-Higgs effect.
To understand and develop the geometrical ground of supersymmetry and supergravity D.V. Volkov formulated the basic concepts of differential geometry of superspace, which in addition to Grassmann-even (bosonic) space-time coordinates is parametrized by Grassmann-odd (fermionic) variables.
The development of supergravity and superstring theory showed that eleven and ten are the most appropriate dimensions of space-time for these models to live in, and in the end of the Seventies Volkov initiated research on the problem of spontaneous compactification of extra space dimensions and proposed a mechanism of spontaneous compactification in super-Yang-Mills models interacting with supergravity based on the "embedding" a gauge field connection into the spin connection of the compactified subspace.
The spin structure of physical theory was always a special topic of Volkov's interests. Among other one may mention his rediscovery of an odd Poisson bracket (the Buttin bracket), which he showed to be useful for an alternative formulation of a wide class of Hamiltonian systems, including hydrodynamics.
He also made a contribution into the development of the relativistic field theory of particles with fractional statistics and spin.
In the end of the Eighties D. V. Volkov advocated and developed ideas on the importance of the role of twistors in the structure of the theory of superparticles and superstrings. This allowed to elucidate the geometrical nature of a mysterious fermionic "kappa"-symmetry of superparticles, superstrings and in general super-p-branes as local supersymmetry of their worldvolumes, and to make a progress in solving the problem of the covariant quantization of superstrings.
As a member of scientific councils, editorial boards of scientific journals and an organizer of theoretical seminars at Kharkov State University D. V. Volkov devoted a lot of his time and energy to the organization and promotion of scientific and public activities.
In 1988 D.V. Volkov was elected a Member of the Ukrainian Academy of Sciences. He was the Honored Scientist of Ukraine, and his talent and devotion to science were given credit by the State having awarded him the Order of Red Banner of Labor and medals.
D.V. Volkov published more than 170 articles in various subjects of theoretical physics. Many of them were written in collaboration with other theorists and pupils of the theoretical school he founded. His strength, enthusiasm and transparent presentation of new fresh scientific ideas, which he was always full of, inspired his students and colleagues not only to work hard on their development but also to pause their own original and interesting theoretical problems. D. V. Volkov was always open to the discussion of the very different problems. He was able to grasp the essence of the problems and very often suggested original approaches to their solution. This is why many famed scientists have considered him as his teacher. The scientific school established by D.V. Volkov in Kharkov is well known all over the world.
Science always occupied an exclusive place in Volkov's life. He jealously guarded its purity and was strongly opposed to any and all breaches of scientific ethics and the intrusion into the field of science of bureaucratic attitude.
In his scientific pursuits D.V. Volkov was driven by an extraordinary intuition, a profound feeling of beauty and aspiration to harmony. His creative work was veiled by romanticism that attracted many colleagues from the world scientific community.
As a person, D.V. Volkov combined a genuinely keen intellect with modesty and the highest human principals. He always expressed respect, kindness and sincere desire to be helpful in difficult issues. He profoundly knew classical literature, Hindu philosophy, and practised yoga. He was interested in the mysteries of human psyche and the power of self-suggestion, which he used to heal the body. This helped him to be optimistic and to work hard until the very last day of his life.