corresponding member of the Russian Academy of Sciences (RAS), and chief researcher at the A F Ioffe Institute of Physics and Technology (IPT) RAS, passed away on December 19, 2021. Vadim L'vovich was born on June 4, 1934 in Leningrad. He was the son of the well-known physicist Lev Emmanuilovich Gurevich. In 1956, V L Gurevich graduated from the Physical Department of Leningrad State University and began working at the Institute of Semiconductors of the USSR Academy of Sciences (ISAS). In 1960, he defended his candidate thesis and, in 1965, his doctoral thesis; in 1971, he was conferred the rank of professor. The same year, Vadim L'vovich organized the Sector of Physical Kinetics at ISAS. After the ISAS and the A F Ioffe Physical Technical Institute united in 1972, this sector moved over to PTI, where V L Gurevich had been working till the end of his life. His most well-known achievements in theoretical physics (together with Yu A Firsov) include the prediction in 1961 of magnetophonon resonanceÐa new type of oscillation of a conductor's kinetic coefficients in a strong magnetic field due to resonant energy absorption upon the transition of charge carriers between Landau levels with the participation of longitudinal optical phonons. As a result, specific magnetophonon oscillations of magnetic resonance, periodic in magnitude, inverse magnetic field, were observed in some semiconductors. This important phenomenon was found in a whole number of materials and underlay the method of magnetophonon spectroscopy of electrons and phonons. Studies of magnetophonon resonance in semiconductors, carried out together with experimentalists, were reported by A V Gurevich in 1964±1965 at academician P L Kapitza's seminars at the Institute of Physical Problems, at FIAN, and at a section of the Division of General and Applied Physics of the USSR Academy of Sciences. In recent years, studies of magnetophonon oscillations have been concentrated on twodimensional nanostructures and other low-dimensional systems, e.g., graphene. Together with V G Skobov and Yu A Firsov, Vadim L'vovich predicted giant ultrasound absorption oscillations in metals in a magnetic field and developed a theory of this effect. This interesting and at first glance unexpected effect turned out also to be important for a certain type of electromagnetic waveÐso-called helicons. Well known are studies by Vadim L'vovich and his coauthors on the theory of ultrasound amplification by the drift of charge carriers in semiconductors. In these works, he formulated a consistent linear and nonlinear theory of the amplification effect in different regimes. For a series of studies on the development of theoretical bases of acoustoelectronics, V L Gurevich (along with I A Viktorov, Yu V Gulyaev, and V I Pustovoit) was awarded the 1974 State Prize of the USSR. The abovementioned studies do not at all exhaust the scientific achievements of V L Gurevich. Studies on theory fluctuations, the theory of dielectric relaxation, the theory of low-temperature properties of dielectric and metal glasses, superconductor kinetics, and others should also be mentioned. In a series of studies, V L Gurevich and his disciples S V Gantsevich and R V Katilyus constructed a consistent theory of fluctuations near a nonequilibrium but stationary state. A specific correlation of fluctuations due to electronelectron interaction was examined. An important role was played by V L Gurevich's works conducted together with his disciple A K Tagantsev on the dielectric relaxation theory, developing the theory of highfrequency losses in dielectric (and ferroelectric) crystals. A systematic analysis for crystals of different symmetries is presented in the frequently cited review in the journal Advances in Physics and also in V L Gurevich's monograph, Uspekhi Fizicheskikh Nauk 192 (2) 229 ± 230 (2022) Translated by M V Tsaplina PERSONALIA PACS number: 01.60.+q

theoretical physicist and corresponding member of the Russian Academy of Sciences (RAS), Igor Ekhiel'evich Dzyaloshinskii. A disciple and colleague of the legendary Lev Davidovich Landau, one of the founders of the Institute of Theoretical Physics (ITP) of RAS, editor of the journal Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki (ZhETF Ð J. Exp. Teor. Phys.) and Pis'ma v ZhETF (JETP Lett.), professor at Moscow Institute of Physics and Technology (MIPT), the faculty of Mechanics and Mathematics of Lomonosov Moscow State University (mech.math. MSU), and theUniversity of California, Irvineì this is a short list of highlights in the scientiéc biography of Igor Ekhiel'evich. The scientific interests of Dzyaloshinskii cover the whole spectrum of condensed media theory; most of his papers have been widely recognized. Already in his younger days, Dzyaloshinskii became a leader in the community of the physics of magnetic phenomena and presented such results as the prediction of the `magnetoelectric effect,' the introduction of the `Dzyaloshinskii ±Moriya interaction,' and the theory of helical superstructures and commensurability effects. This topic is in the list of his publications for today: the epoch of multiferroics that came in the 2000s was, in fact, based on the predictions made more than half a century before by the young scientist I E Dzyaloshinskii. These studies were included in the candidate thesis Dzyaloshinskii defended in 1957. When speaking at the defense, Landau, who was not lavish in giving praise, said that Dzyaloshinskii was one of the most talented young theoreticians whom he had met in recent years. During that same time, the temperature diagram technique was developed. It was included in the written (together with A A Abrikosov and L P Gor'kov) handbook of several generationsÐMethods of Quantum Field Theory in Statistical PhysicsÐthat was awarded the 1989 L D Landau Prize. The book (``AGD'' or the ``Green Book'' as referred to by many generations of students, postgraduates, and research workers at ITP) laid foundation of the scientific language used to date by theoretical physicists around the world. The fundamental contributions due to Igor Ekhiel'evich involve the microscopic theory of van der Waals forces, onedimensional systems of interacting particles, quantum liquids and crystals, spin glasses, topological defects in magnets and liquid crystals (incidentally, it was precisely Dzyaloshinskii who introduced in Russian theoretical physics the idea that liquid crystals are an important area of application of general principles), exactly solvable models, an original renormalization group for high-temperature superconductors, states with time reversal symmetry violation. The scientific and pedagogical achievements of I E Dzyaloshinskii are well known and, in particular, were described in detail in previous well wishes marking milestones. It so happens that most of us (disciples and colleagues of I E Dzyaloshinskii) took part in these very celebrations in the journal Uspekhi Fizicheskikh Nauk (UFN) (see UFN 162 (1) 139 (1992); UFN 171 (2) 227 (2001); UFN 181 (2) 231 (2011)) (Physics±Uspekhi 35 (1) 49 (1992), Physics±Uspekhi 44 (2) 213 (2001), Physics±Uspekhi 54 (2) 221 (2011)). However, new interesting and important work by Dzyaloshinskii appeared recently. In particular, noteworthy are two of his studies that predicted theoretically (and then revealed experimentally using muon spectroscopy methods in an etalon Cr2O3 magnetoelectric) a very interesting and nontrivial phenomenon. Namely, it turns out that, in a certain geometry, electric charges induce a magnetic field with quadrupole and monopole symmetry on a magnetoelectric antiferromagnet surface, both in the sample itself and in the surrounding space. I E Dzyaloshinskii continues to work and, in this milestone year, is finishing preparation of a paper, in collaboration with an international group of experimentalists, on the inverse electrocaloric effect in ion liquids (predicted theoretically in an earlier study undertaken by Dzyaloshinskii and Obukhov). Uspekhi Fizicheskikh Nauk 191 (2) 223 ± 224 (2021) Translated by M V Tsaplina PERSONALIA PACS number: 01.60.+q

Mathematical Sciences, and author of numerous reviews in Uspekhi Fizicheskikh Nauk (UFN) [Physics±Uspekhi] journal, Moisei IsaakovichKaganov, passed away onAugust 31, 2019 at the age of 98. Moisei Isaakovich became famous for his brilliant work on the physics of metals and dielectrics and the physics of magnetic phenomena. His scientific style was characterized by a broad view of the subject under study, an original approach to problems, and an independent way of thinking. Moisei Isaakovich will also remain in our memory as a remarkable popularizer of science. In his popular scientific books and papers, he comprehensively presented contemporary scientific problems and achievements for a wide range of readers and, which is particularly important, infected many generations of the readers of the journal Kvant (Quantum) with his love of science and cognition of the world. Moisei Isaakovich Kaganov (MIK) was born on June 4, 1921 in Kharkov. In 1939, he was admitted as a student to the Department of Physics at the Kharkov State University, but his studies did not last long. In December of the same year, MIK was conscripted into the army. He was in the war from beginning to end, serving till early 1946. In 1946, MIK returned to the university and, having done two diploma studies with his fellow student Viktor Moiseevich Tsukernik, graduated in 1949. This work and friendship between students were the beginning of their years-long fruitful collaboration in a whole number of fields, mainly in the theory of magnetic phenomena. The subject of one study about absorption of electromagnetic radiation by a spin wave system was proposed by Aleksandr Ilyich Akhiezer, and another one concerning the permittivity of a polycrystal was proposed by Ilya Mikhailovich Lifshitz. MIK considered I M Lifshitz to be his teacher. The cooperation with I M Lifshitz lasted many years and with time transformed into a strong friendship. Simultaneously, MIKworked a long time together with A I Akhiezer. In October of 1949,MIK began working at the Ukrainian Institute of Physics and Technology (UIPT), where he remained till April 1970. In 1970, invited by P L Kapitza, he and I M Lifshitz left for Moscow for the Institute of Physical Problems (IPP, now Kapitza Institute), where he worked for 24 years until his retirement in 1994. Both in Kharkov and in Moscow, MIK combined his scientific work with teaching activity. He first taught at Kharkov State University and then became a professor at Lomonosov Moscow State University, where he delivered courses on the electron theory of metals and quantum solid-state theory, both very popular with students. After MIK retired in 1994, he went to Boston in the USA, where one of his daughters had settled. The range of MIK's scientific interests spanned from the problems of classical electrodynamics of continuum media to practical problems of the physics of metals. In the early 1950s, at the cryogenic laboratory of UIPT, experiments on solidstate physics were started, and MIK, together with I M Lifshitz, got involved in the electron theory of metals. This became a basic subject for MIK for many years. One of his first papers in this field that became widely known was ``Kinetics of superconductivity destruction'' (I M Lifshitz, M IKaganov,Dokl. Akad. Nauk SSSR, 1953, v. 90, p. 579), in which the authors calculated the electromagnetic field distribution in a layer of normal metal emerging on a sample surface when superconductivity gets destroyed. In a normal metal layer, either a normal or an anomalous skin effect is realized, depending on the field oscillation frequency and the electron free path. According to MIK, he got to take part in that study as an expert on the anomalous skin effect. MIK returned to the skin effect time and again. Together withMYa Azbel', he formulated the theory of an anomalous skin effect in metals with an arbitrary electron spectrum (Dokl. Akad. Nauk SSSR, 1955, v. 102, p. 49). Together with VMTsukernik, he solved the problem of the influence of thermoelectric forces on the skin effect in metals (Zh. Eksp. Teor. Fiz., 1958, v. 35, p. 474 [Sov. Phys. JETP, 1959, v. 8, Uspekhi Fizicheskikh Nauk 190 (2) 221 ± 222 (2020) Translated by M V Tsaplina PERSONALIA PACS number: 01.60.+q

Владимир Валентинович Лебедев (к 60-летию со дня рождения), Андреев А.Ф., Габитов И.Р., Захаров В.Е., Иорданский С.В., Кац Е.И., Колоколов И.В., Коршунов С.Е., Трунин М.Р., Фалькович Г.Е., Фейгельман М.В., Хмельницкий Д.Е., Элиашберг Г.М.

Всеволод Феликсович Гантмахер (к семидесятилетию со дня рождения), Абрикосов А.А., Андреев А.Ф., Горьков Л.П., Долгополов В.Т., Иорданский С.В., Кведер В.В., Левинсон И.Б., Осипьян Ю.А., Рашба Э.И., Тимофеев В.Б., Хмельницкий Д.Е., Элиашберг Г.М.

Conductances of the equivalent samples differ randomly (Stone 1985). At zero temperature these fluctuations were found to be of the order ofe 2/h for samples of arbitrary size and form (Altshuler 1985; Lee and Stone 1985). Experimentally such fluctuations manifest themselves as e.g. the reproducible aperiodic oscillations of the given sample conductance in magnetic field (Webbet al 1985; Stone 1985). These oscillations can be understood in terms of the correlation function (Lee and Stone 1985; Altshuler and Khmel’nitskii 1985) of the conductances in different fields. The characteristic field scale of the aperiodic oscillations corresponds to the unit magnetic flux through the sample.