SovietRxiv · Open Access in English
Rediscovering the Soviet scientific archive, in English
25357 full-text translations 14926 English PDFs 22539 abstracts
Showing 50 of 25357 papers
The paper studies a rank-one non-self-adjoint perturbation of the operator of multiplication by the independent variable in L2 on the real line, assuming analytic continuation and strip-type square-integrability conditions on the perturbing vectors. It characterizes nonreal eigenvalues as zeros of a…
This paper examines the stability of rotating self-gravitating bodies of revolution under radial perturbations, including perturbations that cause crossing of mass layers. Using an energy method for systems of spherical and cylindrical layers with conserved angular momenta, the authors show that rad…
This study examines how strongly mica substrates orient the growth of thin bismuth films when the mica surface is separated from the deposited metal by an intermediate organic layer. Bismuth was vacuum deposited on mica coated with celluloid layers of varying thickness, on coated glass, and in a sec…
The paper develops several parameterized analogs of Stirling’s formula for the gamma function, motivated by applications requiring expansions in variables other than the argument itself. It derives asymptotic expansions for the gamma function and its reciprocal using a shift parameter, with coeffici…
This note studies how restrictions on subgroups of finite groups determine the structure of the whole group, with particular attention to solvability, maximal subgroups, and classes of finite p-groups. It introduces several auxiliary classes, including generalized Schmidt and Frobenius groups, E-gro…
The paper develops duality formulas for variational problems in which an integral functional is minimized subject to an integral constraint. Using Young transforms and convexity, it proves that the value function of a basic calculus of variations problem can be represented as a maximum over a scalar…
The paper extends a quadrature identity for trigonometric polynomials, previously shown to include M. Riesz’s formula as a special case, to analytic functions associated with a finite plane domain and to half-integer trigonometric polynomials. Using Faber polynomials and a shift operator defined thr…
The paper considers the problem of maximizing a linear function over a closed bounded convex body in finite-dimensional Euclidean space. It proposes a cutting-plane procedure that starts from an enclosing polyhedron and an interior point, repeatedly solves a linear programming relaxation, and, when …
This paper studies invariant subspaces of simple dissipative Volterra operators whose imaginary components are nuclear, with emphasis on the nonunicellular case. Using characteristic operator functions, their divisors, and relations between type and weight, it develops lattice operations for invaria…
This note studies the maximal minimum norm among ideal classes in imaginary quadratic fields, focusing on effective lower bounds for the quantity defined by the least norm in each class. Building on analytic identities for Epstein zeta type sums attached to reduced binary quadratic forms, the author…
This paper examines how heating under high pressure affects defect-related physical properties of natural and synthetic diamonds, with emphasis on nitrogen impurities and associated optical and paramagnetic centers. Natural Yakut diamonds and several synthetic diamond specimens were treated for seve…
This paper investigates the angular and energy distributions of secondary ions emitted when heated tungsten and molybdenum targets are bombarded at glancing incidence by alkali ions with energies of 1 to 3 keV. Using movable-probe angular measurements and electrostatic analysis of energy spectra, th…
This paper analyzes high-rank moments of the molecular distribution function in a weakly rarefied gas near local equilibrium. Using a Hermite polynomial expansion and the 56-moment system of equations for small Knudsen numbers, it solves the linearized relations for second, third, fourth, and fifth …
The paper studies relations between the coefficients of extremal polynomials on the interval [0,1] and the number of their Chebyshev alternants. Using Voronovskaya’s functional method together with convex geometric arguments, it characterizes projections of the unit ball of polynomials with bounded …
This note studies extremal problems for univalent analytic functions and related classes of quasiconformal mappings. Using variational methods, it characterizes extremal slit mappings in the unit disk, relates them to quasiconformal extension problems with prescribed interpolation data, and proves c…
This paper studies the stability of inverse problems in geometrical seismology for a spherically symmetric Earth, where seismic velocity is to be inferred from hodographs. It treats separately the cases of a surface source and a deep source, formulating the corresponding integral equations and using…
This paper addresses the construction of high-order difference schemes for direct computation of discontinuous solutions of nonlinear hyperbolic systems in divergence form, motivated by the oscillations and smearing associated with lower-order methods. It develops an explicit three-stage, five-point…
This note studies approximation of continuous periodic functions by linear methods, focusing on relations between semiadditive bounded functionals, best trigonometric approximation, and moduli of smoothness. It proves general theorems in which assumptions verified only on trigonometric polynomials y…
This note addresses the abstract characterization of relativized semigroups equipped with multiplication and the three relations corresponding to semicompatibility and first and second projection inclusion for partial transformations. It develops an elementary, though infinite, system of axioms for …
This note studies a convolution type integral equation on the real line with different kernels acting on a finite partition of the integration domain, in function spaces including Lebesgue, bounded, continuous, uniformly continuous, and vanishing continuous functions. The equation is reformulated as…
This paper treats an axially symmetric elasticity problem for an infinite elastic space cut along part of a spherical surface. Using Trefftz displacement potentials and analytic functions of a complex variable, the authors derive integral representations for displacements and stresses and reduce the…
This paper reports an experimental determination of the fast neutron spectrum in the core of a highly enriched uranium fast reactor, with emphasis on estimating the fraction of neutrons at energies up to 24 MeV. The authors use threshold indicators, fission chambers, and activation measurements to o…
The paper develops a group-theoretic and functional formulation of free quantized spinor fields with \(2(2s+1)\) components for arbitrary spin, motivated by later study of the covariant structure of causal \(S\)-matrix elements. Using a rigged Hilbert space induced by a unitary irreducible represent…
This paper studies linear homomorphisms between linear topological spaces, with emphasis on closedness, products, powers, and restrictions of such operators. It proves that a homomorphism with closed kernel and closed range is a closed operator, establishes conditions under which products of homomor…
This note refines and extends results on estimation from grouped samples to multidimensional distributions depending on a vector parameter. It formulates maximum likelihood estimation after partitioning the observation space into finitely many cells, gives conditions for existence and uniqueness of …
This paper examines whether the westward drift of the geomagnetic field is a real geophysical phenomenon and what its existence implies for interpretations of dipole and non-dipole components of the main field. Using archaeomagnetic secular variation curves, especially inclination data from regions …
This paper studies Lyapunov stability in the autonomous determination of the coordinates of a moving object by an inertial navigation system with a horizon-stabilized platform. The nonlinear equations for latitude, longitude, and platform orientation are transformed using Rodrigues-Hamilton paramete…
This paper examines how exchange interactions between magnetic ions can affect the relativistic shift of the Mössbauer spectrum, particularly through changes in spin ordering at magnetic transition temperatures. Using prior theoretical arguments based on a Debye phonon model and nearest-neighbor exc…
This paper studies nonlinear equations of the form x = BF(x) in separable locally convex spaces embedded in a Hilbert space, where F maps into the strong dual and B is a bounded linear operator whose Hilbert-space restriction has positivity or quasi-positivity properties. By reducing the equation to…
This note studies the asymptotic behavior of a generalized \(L\)-norm integral associated with sequences of trigonometric polynomials and functions of bounded variation whose variation is concentrated near two symmetric points. It proves a uniform asymptotic formula for these integrals, with a remai…
This paper studies a class of pseudodifferential operators of principal type characterized by a priori Sobolev estimates with loss parameter δ. It gives necessary and sufficient algebraic conditions on the principal symbol at characteristic points for the estimate with δ = 2/3, using auxiliary nonex…
This paper studies linear polynomial operators on spaces of analytic functions and their relation to Faber polynomial expansions in a finite domain with simply connected complement and rectifiable boundary. A shift operation is defined through the conformal mapping of the exterior of the domain, ext…
This paper studies approximation viscosity in finite-difference schemes for linear hyperbolic systems, focusing on whether numerical dissipation preserves contact discontinuities. Using the first differential approximation of a general difference scheme, the authors define property K and a stronger …
This paper studies finite symmetry groups of general linear homogeneous second order partial differential equations with nondegenerate principal tensor. By interpreting the principal coefficients as a Riemannian metric and using equivalence transformations involving conformal changes of the metric a…
This note generalizes inverse approximation theorems for rational approximation on bounded closed subsets of the complex plane whose complement has finitely many components. Using Green functions, Dirichlet problem solutions, and moduli of continuity tied to level curves of the complementary domains…
This paper describes a digital computer experiment modeling the spread of a large influenza outbreak across 128 major Soviet cities connected by an approximated transportation network. The model uses a system of epidemic equations incorporating city populations, intercity travel, duration of illness…
This study examines the external heavy atom effect on intercombination transitions in porphyrins and metalloporphyrins, using etioporphyrin I and related complexes in alkyl iodide solvents. Fluorescence quenching, lifetime measurements, low-temperature phosphorescence spectra, and pulse spectroscopi…
The paper extends the notion of mappings of type s, previously studied for normed spaces, to separated locally convex spaces by defining them through images of neighborhoods as strongly nuclear sets. It establishes several equivalent characterizations, including representation by rapidly decreasing …
This paper analyzes quasistationary nuclear states in an upper conical adiabatic potential well arising near intersections of electronic terms of the same symmetry, with emphasis on triatomic systems near an equilateral configuration. By separating angular variables and imposing single-valuedness of…
This paper studies stability and dissipativity of nonlinear impulsive control systems with pulse-width, frequency-pulse, amplitude, time, and phase modulation, including systems whose linear parts may contain distributed-parameter elements. It formulates sufficient frequency-domain conditions, expre…
The paper studies large deviation limit theorems for normalized sums of independent, not necessarily identically distributed random variables, in settings where the classical Cramér exponential moment condition may fail. It derives integral and local asymptotic formulas comparing tail probabilities …
This paper analyzes the velocity field generated when a finite-amplitude plane shock wave strikes a stationary thin body symmetric about a plane in an unbounded compressible medium. Under small perturbation and irrotational-flow assumptions, the problem is linearized and formulated for the velocity …
The paper studies a dimension invariant, denoted Dind, proposed by A. V. Arkhangel’skii, which combines covering and inductive approaches to topological dimension. It proves that for normal spaces the large inductive dimension satisfies Ind X ≤ Dind X, and that for perfectly normal spaces the two di…
The paper examines possible mechanisms by which electron irradiation produces complex radiation defects in silicon, focusing on secondary associations formed from vacancies and interstitial atoms rather than on unstable primary defects. Using the McKinley-Feshbach scattering cross section and a Kinc…
The paper studies continuation of solutions to nonlinear mixed boundary value problems for second order hyperbolic equations in a plane strip when a boundary nondegeneracy condition fails at a finite time. It analyzes the resulting loss of classical continuation, proves blowup behavior of first deri…
The paper studies periodic boundary value problems for second order ordinary differential equations with summable periodic coefficients, focusing on existence of the Green function, its sign, and related differential inequality methods. Using the distribution of zeros of solutions of the associated …
This paper derives an upper estimate for the modulus of a classical solution of the first boundary-value problem with zero lateral boundary data for a second-order linear parabolic equation in an expanding space-time domain. Under uniform ellipticity and a sign condition on the divergence of the low…
This paper studies embedding theorems for classes of one-variable functions whose first moduli of continuity in Lp are controlled by a given modulus. It establishes sufficient conditions, expressed as weighted series involving the modulus of continuity, for membership in Orlicz-type spaces such as L…
This note studies associative rings without nonzero nilpotent elements through completely prime and completely semiprime ideals. Using m-systems and a Zorn lemma argument, it proves the existence of completely prime ideals over a completely semiprime ideal and shows that every completely semiprime i…
The paper derives a priori boundary estimates for solutions of the Dirichlet problem for uniformly elliptic second order equations with analytic coefficients in domains with analytic boundary. It introduces norms based on iterated tangential analytic differential operators, proves their basic produc…
