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 the construction of wave-field equations covariant under the n-dimensional real unimodular group, motivated by attempts to combine Lorentz and isotopic symmetries and by applications to SU(n) symmetry. It derives covariance conditions for first- and second-order matrix differential…
The paper treats nonstationary diffusion in plane multilayer media whose diffusion and linear interaction coefficients vary discontinuously from layer to layer. It generalizes an operational method previously used for heat conduction without sources by applying layerwise exponential substitutions an…
This note studies the partially ordered set of attracting sets, defined as omega-limit sets of points, for a continuous self-map of an interval. It formulates structural properties of this order, including the existence of minimal and maximal elements in maximal chains, classifications of maximal el…
This note studies lower bounds for the complexity of problems related to systems of linear equations over the field with two elements, considering both the decision problem of whether the determinant is zero and the problem of finding the solution when it is unique. Using a construction related to N…
This paper estimates geothermal heat flow through the bottom sediments of Lake Baikal, a region marked by strong seismicity, crustal disequilibrium, and active tectonic movement. Measurements were made in 1965 at 11 deep-water stations using an oceanographic gradient probe, with sediment thermal con…
This note proves a multidimensional analogue of a classical convergence theorem for holomorphic functions, formulated for sequences of harmonic functions in three variables. It shows that if selected first partial derivatives of a harmonic sequence converge to zero under specified uniform and pointw…
This paper studies a nonlinear programming problem in which the objective is the sum of a linear function and a fractional linear term under convex constraints, with emphasis on the case of linear equality constraints and nonnegativity. It establishes basic properties of the fractional linear object…
This note studies the representation of continuous linear functionals on spaces of holomorphic functions in convex domains of complex Euclidean space. For a convex domain containing the origin, it introduces a conjugate set defined by nonintersection with complex hyperplanes and uses an integral rep…
This note addresses the decision problem for fragments of the narrow predicate calculus, comparing satisfiability and finite satisfiability for classes defined by quantifier prefixes and predicate vocabularies. It proves that formulas without equality with prefix pattern forall exists forall followe…
This paper studies direct and inverse scattering for multidimensional partial difference equations defined by a bounded self-adjoint finite-difference operator with a finite real perturbation. Using resolvent kernels and a limiting absorption principle, it establishes existence and uniqueness of sol…
This paper studies generalized differentiation and quasilinear differential operators for functions whose first generalized derivatives are locally finite measures, with particular attention to discontinuous functions. It introduces upper and lower representatives defined through directional average…
Systematic balloon and rocket measurements from 1958 to 1963 are used to examine infrared radiation from the upper atmosphere over 0.8 to 40 microns at altitudes of 25 to 500 km. The observations indicate intense, layer-like infrared emission above 200 km, with maxima near 250 to 300 km, 420 to 450 …
This paper studies steady wind-driven circulation in a rectangular homogeneous ocean of constant depth, with attention to western boundary intensification and equatorial effects. The governing elliptic boundary-value problem for the integral stream function is solved numerically by converting it to …
This paper studies the inverse spectral problem for a half-line Dirac system with locally integrable real coefficients. It first shows that the spectral function does not determine a general system uniquely, because orthogonal transformations preserve the spectral measure, and therefore reduces the …
This paper studies an inverse scattering problem for a non-self-adjoint Sturm-Liouville operator on the half-line with complex potential satisfying an exponential integrability condition and Dirichlet boundary condition at the origin. It introduces suitable notions of denominator, scattering functio…
This paper describes representations of commutative symmetric separable Banach algebras with identity in a separable Pontryagin space of finite negative index. It first recalls the Hilbert space case as a direct integral over the space of symmetric maximal ideals, then analyzes the indefinite case b…
This paper examines recombination in CdS and argues that carrier capture at a single sensitizing recombination center can proceed through two parallel mechanisms rather than through distinct centers. Using kinetic measurements of infrared photocurrent quenching at 1.4 and 0.9 eV in CdS single crysta…
The paper studies the Cauchy problem for second order hyperbolic equations whose type may degenerate on the initial line, with particular attention to conditions ensuring well posedness when lower order terms are present. It formulates refined integral criteria for existence, uniqueness, and stabili…
The paper determines the crystal structure of hydrothermally synthesized cadmium tungstate, CdWO4, as an end member of the monoclinic wolframite-type tungstates with medium divalent cations. X-ray precession data and Patterson and difference Fourier analyses are used to locate Cd, W, and O atoms in …
This paper studies integral representations for functions of exponential type expressed in polar coordinates in two complex variables, including functions regular in a half-space and entire functions. It introduces a harmonic function defined by an integral transform and shows, through analytic cont…
This paper examines the possibility of a hydrodynamic thermal explosion in steady axisymmetric flow of a chemically inert non-Newtonian fluid through a cylindrical tube, assuming a power-law rheology and a strong exponential temperature dependence of the consistency coefficient. By nondimensionalizi…
This note studies multiplier methods for summing Fourier series, focusing on estimates for the mean absolute value of the associated kernel under convexity or concavity assumptions on the multiplier array. It proves an upper bound in terms of the final multiplier, derives a simple sufficient conditi…
This paper analyzes the nonlinear quasiclassical equations describing the interaction of an electromagnetic field with a two-level medium, neglecting relaxation effects and avoiding preliminary linearization. Using conservation relations for probability and total matter-field energy, the authors red…
The paper applies Chaplygin’s method to a nonlinear boundary value problem arising in the equilibrium of a membrane without contour chain forces. It constructs explicit lower and upper functions that bound the solution, establishes uniqueness in the considered smoothness class, and develops a monoto…
This paper studies solvability of nonlinear operator equations of the form BF(x) = x in a Hilbert space, where B is a linear self-adjoint operator that may be unbounded and indefinite. Extending earlier variational results that required boundedness and strong restrictions on the positive spectrum, i…
The paper develops a framework for defining second order elliptic differential operators in functional derivatives on infinite dimensional spaces, including cases where the coefficient operator is unbounded. Using Hilbert space scales and trace class criteria, it defines operators of the form involv…
This paper estimates the frequency dependence of absorption coefficients for longitudinal seismic waves propagating in the Earth’s mantle, focusing on Pn and P waves. Using amplitude spectra from records of 1958 underground nuclear explosions in Nevada, the study analyzes changes in spectral-compone…
This paper studies equilibrium measures and equilibrium potentials for closed subsets of an n-dimensional parallelepiped with respect to a broad class of decreasing singular kernels satisfying an integrability condition and an additional growth monotonicity condition. Using capacity, variational arg…
This paper studies limiting regimes of nonlinear control systems with several scalar nonlinearities that may be discontinuous and are constrained by sector-type monotonicity conditions. Solutions are defined in an augmented sense allowing values between one-sided limits, so that sliding regimes can …
The paper studies global regular realization in three-dimensional Euclidean space of infinite strips in complete two-dimensional metrics of negative curvature, with the metric written in semigeodesic form and satisfying bounded \(C^{4,1}\) regularity and curvature bounds between negative constants. …
The paper studies refinements of Sobolev type embedding theorems by replacing target Lebesgue spaces with rearrangement invariant Lorentz type spaces defined through decreasing rearrangements. It establishes embedding relations for the spaces \(L(\lambda_1,\lambda_2,p)\), proves a strengthened poten…
The paper studies Cauchy problems for general linear systems of partial differential equations in Gevrey spaces, focusing on sufficient and necessary regularity weights for solutions analytic in one variable. Using the quasi-characteristic polynomial and Puiseux expansions of its roots, it gives a s…
The paper addresses whether the classical nilpotency of the Frattini subgroup of a finite group extends to finitely generated linear groups, and more generally to linear groups over finitely generated subrings of a field. It develops a refinement of Mal’tsev’s finite approximation method by showing …
This paper studies the energy spectrum of stochastic gravity waves on the surface of an infinitely deep liquid in the weakly nonlinear equilibrium range. Starting from the hydrodynamic equations for the surface displacement and velocity potential, the authors transform to Fourier wave variables and …
This paper reports systematic optical measurements of excitation cross sections for lower helium levels produced by collisions with slow electrons. Using a stationarity relation between level populations, radiative transition probabilities, and measured spectral line intensities, the author derives …
This paper reports measurements of the angular distribution of fission fragments produced when Am-241 is fissioned by neutrons, motivated by comparison with the previously studied odd-odd compound nucleus Np-238. Using an electrostatic accelerator neutron source and glass fragment detectors position…
The paper studies an analytic problem motivated by statistical tests and unbiased estimation, concerning module homomorphisms defined by multiplication by a matrix of holomorphic functions on a bounded polycylinder. For the ring of holomorphic functions satisfying polynomial-type growth estimates ne…
The paper addresses the problem of proving superlinear lower bounds for explicitly defined Boolean functions without imposing special restrictions on the computational basis. It constructs a family of Boolean functions by partitioning variables into logarithmic-size blocks and using distinct conjunc…
This note studies uniqueness for the second and third boundary-value problems for a second-order uniformly elliptic equation with nonpositive zeroth-order coefficient, in bounded domains whose boundary may contain singular points where no boundary condition or regularity is prescribed. It introduces…
This paper extends Pogorzelski’s theorem on the invariance of a weighted Hölder-type class of functions under Cauchy-type singular integrals. For a finite system of arcs with possible corner or nodal endpoints, it proves that an integral with a shifted singularity preserves the class under specified…
This paper studies extremal problems for univalent conformal mappings of annuli and more general multiply connected domains under prescribed separation and containment conditions on boundary components and marked points. It establishes sharp lower bounds for distances between images of boundary circ…
The paper addresses the construction of cubature formulas with regular boundary layers for rational convex polyhedra in arbitrary dimension, where geometric intuition is replaced by lattice and face combinatorics. It develops a framework in which boundary layer coefficients are grouped by sublattice…
