Mstislav Vsevolodovich Keldysh

Born Jan. 28 (Feb. 10), 1911, in Riga. Soviet scientist in mathematics and mechanics. Academician of the Academy of Sciences of the USSR (1946; corresponding member, 1943). Member of the academy’s presidium since 1953; the academy’s vice-president in 1960–61 and president from 1961 to 1975. Three times Hero of Socialist Labor (1956, 1961, 1971). Member of the CPSU since 1949. Son of V. M. Keldysh.

M. V. Keldysh graduated from Moscow University in 1931. He then worked at the Central Institute of Aerohydrodynamics; at Moscow University, where he became a professor in 1937; and at the V. A. Steklov Institute of Mathematics of the Academy of Sciences of the USSR. In 1953 he became director of the Institute of Applied Mathematics of the Academy of Sciences of the USSR.

Keldysh has conducted numerous fundamental studies in mathematics, numerical analysis, aerodynamics, and oscillation theory. He has made outstanding contributions in working out a number of important problems in aviation, nuclear, and space technologies. A large number of his works have been devoted to oscillations and self-excited oscillations in aircraft structures. In these works he has developed the theory of aircraft flutter, created numerical methods for computing this phenomenon as well as methods of simulating it in wind tunnels, and proposed practical measures to prevent it. Keldysh has also studied the phenomenon of shimmy—the self-excited oscillations of the nosewheel of an aircraft’s landing gear—and found simple design Solutions to eliminate it. In aerohydrodynamics he was the first to study the effect of the medium’s compressibility on the aerodynamic characteristics of a streamlined body and to generalize the Zhukovskii theorem on lift force. He obtained fundamental results in the hydrodynamics of a body moving beneath a fluid’s surface and of the wave resistance, in the theory of impact of a body on a fluid, in the theory of wing vibration, and in the theory of propellers.

Keldysh’s principal mathematical works deal with the theory of functions of real and complex variables, partial differential equations, and functional analysis. He has posed and answered basic questions on the stability of solutions to the Dirichlet problem for Laplace’s equation. He was the first to find the correct formulations of boundary value problems for elliptic equations that are degenerate at the boundary of the region as a function of the character of the degeneracy. He has obtained important results in the theory of functions of a complex variable and its applications in hydrodynamics. He has solved the problem of uniform polynomial approximation of functions in a closed region and studied the question of mean approximation. Keldysh was the first to demonstrate the completeness of a system of eigenfunctions and associated functions for non-self-adjoint partial differential operators. He has made important contributions to the development of numerical and computer mathematics in the USSR, to the creation of efficient computing methods for problems in nuclear and space technologies, and to the development and execution of space studies.

A member of many foreign academies, Keldysh is an active foreign member of the Academy of Sciences of the Mongolian People’s Republic (1961), a foreign member of the Academy of Sciences of the Czechoslovak Socialist Republic (1962), a foreign honorary member of the Academy of the Socialist Republic of Rumania (1965), an honorary member of the Academy of Arts and Sciences in Boston (USA, 1966), an honorary member of the Academy of Sciences of the People’s Republic of Bulgaria (1966), a foreign corresponding member of the German Academy of Sciences in Berlin (1966), a corresponding member of the Saxony Academy of Sciences in Leipzig (1966), an honorary member of the Royal Society in Edinburgh (1968), and an honorary member of the Academy of Sciences of the Hungarian People’s Republic (1970). He is also an honorary member of various scientific institutions and societies.

Keldysh was a delegate to the Twenty-second, Twenty-third, and Twenty-fourth Party Congresses, at which he was elected to the Central Committee of the Communist Party, as well as a deputy to the sixth through eighth convocations of the Supreme Soviet of the USSR. A recipient of the State Prize of the USSR (1942, 1946) and the Lenin Prize (1957), he has been awarded six Orders of Lenin, three other orders, various medals, and four foreign orders.