Lavrentiev Mikhail A.

Lavrentiev, Mikhail Alekseevich (1900-1980), Soviet scientist in the field of mathematics and mechanics, the organizer of science.

Born on 6 (19 new style) in November 1900 in Kazan, a family of teachers of Mathematics, Technical School, (later a professor of mechanics at first, Kazan, then Moscow University). In 1910-1911, together with his father was in GцІttingen (Germany), where walking to school. Secondary education received in the Kazan commercial school, after it entered the Kazan University (1918). The greatest influence on Lavrent'eva at Kazan University had a professor of mathematics EA Bolotov, DN п?п?п№п?п?пЁп?я€ and N. Parfent'ev. Already here beginning to affect a significant predilection for mathematics Lavrentiev. He taught at the Kazan University, worked as a laboratory mechanical cabinets.

In 1921 his family moved to Moscow and transferred to the physical and mathematical faculty of Moscow State University, in 1922 graduated from Moscow State University.

Still a student in 1921 Lavrent'ev began teaching at the Moscow Higher Technical School (now the MSTU. Bauman), continued teaching until 1929

. Moscow Lavrentiev entered the 'Lusitania' - so playfully called Mathematical School, . created about 1914 outstanding domestic mathematician Lusin (historically Lusitania - the province of the Roman Empire, . the territory of modern Spain and Portugal, . named after the ancient tribe inhabiting it - Lusitania),
. Luzin's research interests relate to the theory of sets and the theory of functions, rapidly developing at the time. A characteristic feature of Luzin as a scholar and teacher, was a collective form of research that promotes production of the new challenges and finding new approaches to old problems. From the school came home galaxy of outstanding mathematicians (II Privalov, VV Stepanov, Aleksandrov, M. Ya Suslin, D. Menchoff, A. Ya, S. Kovner, Uryson, VN Benjamin, Kolmogorov, V. Niemytzki, LV Keldysh (elder sister M.V. Keldysh), Novikov, NK Bari and others), their number is owned and Lavrentiev. In 1923-1926 he - postgraduate Lusin, doing research on set theory, topology (the science of the general mathematical properties of spaces preserved under continuous transformations), differential equations. The first published work (in French) "Contribution a la theorie des ensembles homeomorphes" (On the study homeomorphic sets) was issued in France, 1924. The following seven of his works, executed in the period 1924-1927, were also published in French in the Western European (mainly French) scientific publications - the usual practice at the time Soviet scientists. In 1928 he published, mainly in domestic journals. Communicate with prominent French mathematicians Denjoy, Hadamard, Montel, lectures Goursat, Borel and Julia, participation in seminars on the theory of functions was for him a good school.

Upon returning to Moscow (end 1927) was elected assistant professor of Moscow State University and a member of the Moscow Mathematical Society. Began to read in the MSU course on the theory of conformal mappings (transformations of space, preserving the value of angles). Since 1927 engaged in an important application problem of approximation of functions of complex variable (more than simple functions - polynomials), . By this time the true beginning of his research on the theory of quasiconformal (nearly conformal) mappings, . owing to the pressing needs of the aerodynamics of the increased speed: a model of an incompressible fluid, . used with low flight speeds, . ceased to be fair,
.

In 1928, as part of the Soviet delegation participated in the International Congress of Mathematicians in Bologna (Italy) reported on quasiconformal.

From 1929 became the head of the department and became a professor of the Moscow Institute of Chemical Technology. In the same year began working as a senior engineer of the Central Institute aerohydrodynamic. Prof. NE Zhukovsky (TsAGI). Here he drew the head of the theoretical division TsAGI Chaplygin. These were years of rapid flowering of aircraft and the formation of the theory of flight, aerodynamics research wing, which impacted on future topics of research Lavrentiev. It is from this period, which lasted six years, began his work directly in the field of applied mathematics. He drew in TsAGI and his students, colleagues, and then Keldysh and LI Sedov. In terms of interests Lavrent'ev and his team included such sections hydro and aerodynamics, . as the theory of an oscillating wing, . movement of the wing under the surface of heavy fluid, . solid blow on the water, . construction flow, . flowing over an arc of given shape and a number of other,
. The results are further used, in particular, in addressing the problem of flutter. Was found a general method for solving the problem of flow around thin airfoils of arbitrary shape and shows that the greatest lifting force has a wing in the form of a circular arc. Applied problems have stimulated further research on the theory of variational principles of conformal mappings. In 1935 Lavrent'ev published (some in collaboration) 16 articles and reports, a monograph in 2 volumes, program curriculum.

In 1931 became a professor of Moscow State University, who devoted their lives to the university for many years.

Without the protection of the dissertation (on set of scientific works) Lavrentiev in 1934 awarded the degree of Doctor of Technical Sciences, and in 1935 - Doctor of Physical and Mathematical Sciences. In the same became a senior fellow at the Steklov Institute of Mathematics. Steklov Academy of Sciences of the USSR, where he worked for over 25 years. Effect Lavrent'eva this scientific institution, and is now significantly. Since 1934 he headed the department of function theory and has trained a large number of students, . later became outstanding scientists, . including Academician Ishlinskii, . Academician of the Academy of Pedagogical Sciences AI Markushevich, . Corresponding Member of USSR Academy of Sciences, . Academician of Georgian Academy of Sciences Bitsadze,
. By mid-1930 Lavrent'ev became recognized head of the Soviet school of complex variable theory.

In 1939 elected a member of the Academy of Sciences of the Ukrainian Soviet Socialist Republic (SSR) and Director of the Mathematical Institute of the Academy of Sciences of USSR, moved to Kiev. Here he studied the theory of complex variable and its applications. In the Ukraine were launched and Lavrentiev studies related to the mechanics of the explosion, was a scientific school. Taught at Kiev University, Professor (1939-1941 and 1945-1949), from 1941 to 1945 - Head of the Mathematical Department SSR.

During the Second World War with SSR Lavrentiev was evacuated to the Urals city of Ufa. He continued his studies in the field of explosions. Assuming that at high temperatures, the materials behave like a viscous fluid, has developed a hydrodynamic theory of cumulation (cumulative effect - open in the second half of the 19. increased penetrative power of his shell with a special device, . such, . that the collision of a projectile with a barrier formed high (cumulative) of jet propellant gases and melt the metal shell, . Burn down the barrier),
. The results, including the most important - the depth of penetration of the jet in the barrier, given in the article "Cumulative charge and its working principles", 1957. Successfully solved a number of military engineering tasks involved in the creation of domestic HEAT projectile. In the study of characteristics of cumulation was detected phenomenon welding explosion in widespread use in the future.

Attention is also drawn Lavrent'ev and the theory of long waves on the surface of the liquid under the action of gravity. Obtained the first proof of the existence of exact solutions of equations of propagation of a soliton (a solitary surface waves) are given in the article "On the theory of long waves", 1943, then in the article "Before teorii Dovgiy Hvylya" (in Ukrainian), 1947.

In February 1945, returned from evacuation in Kiev, became vice-president of SSR. In this position he stayed until 1948.

In 1946 he was elected academician of the USSR. For research in the field of complex variable theory and the creation of the theory of quasiconformal mappings, he was awarded the Stalin (State) Award. In 1949 awarded the Stalin Prize for the second created his theory of cumulative jets.

In connection with the problem of flooding captured vessels studied the effects of underwater explosion. Pilot tested developed his theory on the academic basis of the Academy of Sciences of Ukraine in Kiev suburb Theophany. It was found the formation of cumulative jets formed during the collapse of the water cavity of the explosion products. Published "The experience of calculating the influence of the depth of immersion in a liquid bomb on its destructive force, 1946. The same period is the emergence of ideas about using braiders charges on the basis of 'wet gunpowder', be a suitable tool when laying trenches for metal cutting, the organization aimed explosions, etc..

Since 1948, working again at MSU. During this period, based on the MSU creates a new university - the Moscow Physical-Technical Institute (MIPT), . played an important role in the preparation of highly qualified staff for new branches of science and technology, . arose in the postwar years,
. This institute Lavrent'ev founded specialization in the theory of explosions, he headed the department of physics of fast processes (1955-1958). Engaged directed explosions. Results are discussed in "On sent by throwing the soil with explosives", 1960.

The equations of mixed type describing the gas flow in the areas of transition through the speed of sound, suggested the use instead of the Tricomi equation model linear equation of mixed type. In 1950 published a paper (co-authored with A. Bitsadze) "On the problem of equations of mixed type."

In 1947, made at the session of the USSR Academy of Sciences report on "Future development of Soviet Mathematics" (published in 1948). Particular attention was given to Computational Mathematics and Technology. Called for the speedy establishment of Institute of Computer Science

. In 1950 elected a director of the Institute of Fine Mechanics and Computer Engineering (founded in 1948 in Moscow), which became the chief designer SA Lebedev, a specialist in electrical and computer engineering, then the USSR Academy of Sciences
. The Institute in the shortest possible time are the first examples of Soviet electronic computers - the ancestor of domestic computers. Managed by the Institute until 1953.

From 1951 to 1953 he was an academician-secretary of the Department of Physical and Mathematical Sciences of the USSR Academy of Sciences of attached great importance, the exclusive attention to the development of what was then the principal directions of science and its specific connection with the practice.

From 1953 to 1955 he worked together with the leader of the Soviet atomic project Academician IV Kurchatov, was deputy chief designer of the Ministry of Medium Machine Building. In 1958, one of the first received the Lenin Prize (on special topics).

In 1955 elected a member of the Presidium of the USSR, from 1955 to 1957 again - the academician-secretary of the Department of Physics and Mathematical Sciences of the USSR.

In 1957, nominated, together with academicians SA Christianovitch and Sobolev, the establishment of scientific complexes in Siberia, especially in areas of intensive development of industry and agriculture. This idea was supported by a number of eminent scientists. May 18, 1957 was adopted by a government decision on the establishment of the Siberian Branch of the USSR, and its chairman was Lavrentiev. He headed the Siberian Branch until 1975 (then was the Honorary Chairman). Siberian Branch became widely known throughout the world, proved to be not only a series of fundamental developments, but their application to the most vital problems of development of Siberia and the Far East and the European part of Russia.

The first in the Siberian Branch joined the Institute of Hydrodynamics (now they. MALavrentjev LIH), organizer and director of which was Lavrentiev. He is the choice of the organizational structure of the institute, its scientific perspective, giving them character and retrieval, and application, determination of appropriate mix of basic research with national economic objectives. Managed by the Institute until 1976.

Supported Lavrent'eva BV Wojciechowski, VV Mitrofanov, M. E. Topchiyanom etc.. the Institute has developed a theory of spin detonation (when traveling in a circular tube the detonation wave front of this kind described in the pipe walls helix).

In this paper, "On a principle of creating the traction force for the movement" (with MM Lavrent'ev, 1962) proposed a mechanical model (a flexible rod in a channel with rigid walls) to investigate the movement of snakes, fish, etc.. Investigated the dynamics of clouds of a nuclear explosion, a theory of self-motion of turbulent vortex rings. Built new models of separated flow around bodies with a stern circulation zone. He was interested also other problems: water waves and their damping by rain, the emergence and development of giant sea waves (tsunami), . fighting forest fires, . prevention of pollution of rivers, . Ecology Construction, . merits of different computer systems, . Organization for Scientific Research, . methods of teaching in higher and secondary education, etc.,
.

With the active participation Lavrent'eva created and Novosibirsk State University (was organized in 1958, the first academic year began in September 1959 lecture of Academician Sobolev). The basis for the student practice began to research institutes of the Novosibirsk Akademgorodok. He has lectured at the Novosibirsk University, professor at the University 1959-1966.

In Novosibirsk Akademgorodok were created initially specialized physical-mathematical, chemical and then boarding school, a club for young technicians. Official opening of the country's first specialized physical-mathematical boarding school (PMS) at the Novosibirsk State University was held in January 1963.

He received the title of honorary citizen of Novosibirsk (1970).

Since 1976 he again worked in Moscow. In the 1976-1980 President of the National Committee of the USSR on Theoretical and Applied Mathematics.

Often been abroad, where he lectured and studied the state of mathematics and mechanics. He was elected a member of 1962-1966, and 1966-1970 vice-president of the executive committee of the International Mathematical Union. He was elected a foreign member of the Czechoslovak Academy of Sciences, . Bulgaria, . Poland, . Finland, . Academy of Sciences in Berlin, Germany (GDR), . AN Liopoldina (GDR), . French Academy of Sciences, . member of the International Academy of Astronautics, . and a member of several other international and national scientific organizations,
.

Posted by a number of monographs and textbooks.

For outstanding achievements in the development of science and the Siberian Branch of USSR Academy of Sciences awarded the title Hero of Socialist Labor (1967). He was awarded five Orders of Lenin (1953, . 1956, . 1960, . 1967, . 1975), . Order of the October Revolution (1970), . four Orders of Red Banner of Labor (1945, . 1948, . 1953, . 1954), . Order of the Patriotic War II degree (1944), . Order of the Legion of Honor degree of Commander (the highest award of France, . 1971), . medals,
.

530 known works Lavrent'eva (academic and journalistic articles, reviews, monographs, textbooks, essays and memoirs, etc.) Many of his students have become outstanding scientists.

Died Oct. 15, 1980 in Moscow, was buried in Novosibirsk.