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
This paper studies boundary value problems for elliptic equations, elliptic equations with a complex parameter, and related parabolic mixed problems in unbounded exterior domains. Under uniform ellipticity, Shapiro-Lopatinskii conditions, and additional assumptions describing behavior at infinity, i…
This paper studies a conjugation problem for three analytic functions connected by boundary conditions on a smooth closed contour through two branches of the square root. The authors reduce an associated jump problem to two classical Riemann boundary value problems, construct canonical factorizing f…
This note establishes embedding theorems for Besov spaces with mixed norm on Euclidean space and for weighted Besov spaces on the half-space. The author defines the relevant spaces through mixed Lebesgue norms and difference norms of derivatives, then states conditions under which functions or their…
The paper studies pseudodifferential operators with a finite group of shifts on a connected manifold with an effective finite group action. By associating such an operator to a group invariant pseudodifferential operator on the product of the manifold with the group, it gives a necessary and suffici…
The paper studies integral operators in \(L_2\) spaces whose kernels satisfy Carleman, semi-Carleman, Akhiezer majorization, and symmetric variants of these conditions. It formulates and solves classification problems giving necessary and sufficient conditions for an operator to belong to each class…
This note studies quantitative characteristics of algorithmic languages, focusing on how briefly algorithms can be encoded and compared through translators between languages. It defines reducibility, message complexity, additive, asymptotic, and multiplicative boundedness of translators, and corresp…
The paper reports an X-ray crystallographic determination of hydrothermally synthesized sodium titanogermanate, Na2(TiO)[GeO4], in order to assess its structural relation to analogous silicates and the role of germanium in tetrahedral coordination. Using three-dimensional Patterson analysis and refi…
The paper argues that a vacuum-like state of matter with energy momentum tensor proportional to the metric and equation of state p equals minus the energy density can serve as the initial state for any of the three Friedmann cosmological models. It analyzes the causal and quantum limits of such a me…
This paper analyzes the pinch effect in a bipolar semiconductor plasma when one or both carrier species are strongly degenerate, a regime not covered by the usual nondegenerate gas model. For an infinite plate carrying longitudinal current, the carrier distribution is reduced under quasineutrality a…
The paper proposes an axiomatic construction of locally Euclidean, locally symplectic, and locally non-Euclidean geometries of constant curvature as instances of the theory of physical structures. It formulates a principle of phenomenological symmetry for a set of points equipped with symmetric or a…
This paper studies one-to-one mappings between affine spaces that carry the family of all translates of a bounded set onto the family of translates of its image. Using an iterative construction of associated centrally symmetric sets, it proves that tangent supporting hyperplanes at suitable extreme …
The paper studies conditions under which a normal subgroup of a finite group admits a complement or, more generally, a complement relative to a specified set of primes. It proves that a normal subgroup has a prime set complement when, for each prime in the set, the intersection with a Sylow subgroup…
The paper applies the contour integral method to multidimensional mixed problems for second order parabolic systems in a three-dimensional domain, with boundary conditions that include a time derivative. Under assumptions on the spectrum of the coefficient matrix, regularity and boundedness of the c…
The paper studies boundary value problems for quasilinear parabolic systems in the Douglis, Nirenberg, and Solonnikov sense, with linear boundary conditions and zero initial data in anisotropic Sobolev spaces. Using an abstract solvability theorem for nonlinear equations in Banach spaces together wi…
The paper extends Efimov-type results on complete surfaces of negative curvature from Euclidean three-space to three-dimensional Riemannian spaces with nonpositive sectional curvature. For a complete surface with negative extrinsic curvature, it derives generalized fundamental equations in asymptoti…
This paper introduces the hysterant operator as a mathematical tool for describing hysteresis-type nonlinearities arising in Prager-Ishlinskii models of elastic-plastic behavior. The authors define an elementary hysterant first for continuous piecewise-linear inputs and then extend it to arbitrary c…
The paper studies normalized equilibrium points in concave n-person games and develops iterative methods generalizing the conditional-gradient approach for computing them under convexity and regularity assumptions. It proves convergence results for three step-size rules, including subsequential conv…
The paper addresses two classical descriptive set theory questions in their formal set theoretic formulation: the existence of an uncountable coanalytic set containing no perfect subset, and the existence of a non-Lebesgue-measurable set of projective type. It proves in Zermelo-Fraenkel set theory t…
This note establishes integral and local limit theorems for large deviations of normalized sums of independent, centered random variables with finite variances. Using three classes of growth functions introduced by Linnik and exponential moment conditions of the form involving h of the summands, it …
This note formulates a general scheme for a method used in several classes of discrete optimization problems, including production allocation, integer linear programming, discrete programming, concave programming, and reliability problems. The problem is to minimize a function on a finite feasible s…
This note analyzes features of the interband Faraday effect in heavily doped semiconductors near the absorption edge, focusing on how electron degeneracy and randomly distributed impurity potentials modify ellipticity and rotation. Using a simple band model with Landau-level summation and a classica…
This note develops partial Fredholm-type solvability results for nonlinear operator equations in Banach spaces with completely continuous operators that possess an asymptotic derivative. Using a finite-dimensional algebraic lemma and the Schauder-Tikhonov fixed point principle, it proves necessary a…
This paper formulates a variational and Hamiltonian representation for the equations of ideal magnetohydrodynamics, extending Davydov’s canonical treatment of ideal fluid hydrodynamics. By introducing a decomposition of the velocity field in terms of the density, magnetic field, scalar potential, an…
This paper extends shortest path theorems for compact simply connected Riemannian manifolds to complete noncompact spaces with positive or nonnegative sectional curvature. It proves that in a complete noncompact Riemannian space with positive curvature bounded above by \(k_1>0\), every geodesic segm…
The paper studies topological Markov chains defined by shifts on the two-sided path space of a connected countable directed graph, focusing on when the supremum of metric entropies is attained by an invariant measure. It first analyzes a class of special graphs through a generating series for return…
This paper studies asymptotic behavior of densities and probability functions for normalized sums of independent identically distributed multidimensional random vectors with nondegenerate covariance matrix. It derives an explicit upper bound for the modulus of the characteristic function under a bou…
The paper determines the crystal structure of landauite from the Burpala massif using X-ray diffraction data, Patterson projections, electron-density maps, and least-squares refinement. It evaluates alternative chemical and symmetry models and finds that the centrosymmetric space group A2/a with the…
This note formulates general theorems on the space of isometric immersions and embeddings of pseudo-Riemannian manifolds, extending results of Nash, Kuiper, Janet, Cartan, Burstin, and Smale-Hirsch type immersion theory. Using bundle-theoretic conditions on isometric morphisms, monomorphisms, and se…
The paper examines the “chain effect” in glancing scattering of argon ions by the [110] atomic chains on the (100) face of a copper single crystal. Using numerical calculations based on earlier scattering models, it analyzes how the reflected ion energy as a function of scattering angle changes with…
The paper studies absolute continuity of measures generated by solutions of differential equations with random Gaussian forcing in finite-dimensional Euclidean space. It compares a linear equation with a corresponding nonlinear equation containing an additional drift term, formulates conditions invo…
This paper studies stability of the residual method for ill-posed linear operator equations of the first kind in Banach spaces, where only a convex closed neighborhood filter of the exact right-hand side is given. The method selects the minimum-norm element among points whose image lies in the presc…
The paper extends a Hartogs type regularity result to generalized analytic functions of several complex variables satisfying first order systems with complex partial derivatives and analytic coefficient functions subject to compatibility conditions. It defines weak solutions through one variable wea…
The paper examines quantities constructed from the Ricci tensor and a separated term containing second derivatives of the metric, arguing that in harmonic coordinates the resulting quantities can be interpreted as gravitational stresses. It derives a decomposition of the Einstein tensor into two par…
This paper studies Lyapunov stability of the zero solution of a periodic analytic system of differential equations whose linear approximation has two purely imaginary characteristic exponents and all remaining exponents with negative real parts. Focusing on Lyapunov’s generally transcendental case, …
This note formulates a multidimensional Plateau problem for a new class of compact sets defined by homological boundary and relative cycle conditions in a compact Riemannian manifold. It proves an existence theorem for a measure-minimizing compact in this class and describes its regular part as a sm…
This paper studies the time-dependent size of plastic zones in elastic-plastic bodies with aftereffect, focusing on a hollow sphere under internal and external pressure and related axially symmetric cylinder problems. Using operator constitutive relations for shear, volumetric response, and hardenin…
This note extends first main theorems in value distribution theory for holomorphic mappings to compact complex target manifolds without imposing Kähler, homogeneous, or projective structure. The main construction proves that on any compact complex manifold with a normalized volume form there is a co…
This paper examines the use of Stark broadening of hydrogen spectral lines as a noncontact optical diagnostic of electric fields associated with turbulent plasma heating by direct discharge current. The authors derive and apply criteria distinguishing quasistatic ion-acoustic fields from high-freque…
This paper presents a method for estimating the spectral width of the infrared luminescence line associated with the iodine atom transition in a photodissociation optical quantum generator operating at 1.315 micrometers. The authors use a Fabry Perot etalon with a time swept interference pattern, re…
This note studies subdifferentials of composite convex functionals on Banach spaces, where a continuous convex mapping into a Banach lattice is composed with a monotone convex functional. It introduces a subdifferential for Banach lattice valued mappings and establishes conditions under which this s…
The paper studies the minimization over a convex compact constrained set of a nonsmooth function defined as the maximum of finitely many continuously differentiable functions. It formulates stationarity in terms of the intersection of the convex hull of active gradients with the conjugate cone of fe…
This paper studies the onset and post-critical development of cellular convection in an infinitely long horizontal gas layer heated from below, taking account of compressibility, the adiabatic temperature gradient, and gas properties beyond the Boussinesq approximation. The authors solve the two-dim…
This paper examines evidence for a low-velocity seismic waveguide in the crust of the Garm region of Central Asia. Using earthquakes from two localized focal zones as plunging sources, the authors construct and interpret systems of mean travel-time curves for longitudinal and transverse waves, suppl…
This paper proposes sensitized photolysis on semiconductor surfaces as a basis for long-wavelength photography, extending the two-stage mechanism of silver-halide latent-image formation to systems where adsorbed metal ions are reduced by photoexcited carriers. The authors examine photoreduction of s…
The paper studies approximation of continuous and differentiable functions on the unit cube by generalized polynomials, defined as finite linear superpositions of functions of fewer variables with respect to prescribed one variable systems. It establishes existence and characterization results for b…
The paper develops a refinement of uniform homology groups for metric spaces, motivated by the inability of earlier groups to distinguish manifolds whose bounding chains grow with different diameter orders. For each admissible order of growth, it defines subsets determined by cycles requiring chains…
This note studies isometric immersions of two-dimensional Riemannian metrics into Euclidean three-space by surfaces of class C1 under an added condition of regularity with respect to affine transformations. It introduces affine regularity and proves structural results for immersions of metrics of bo…
This paper formulates the Einstein equations for spatially homogeneous gravitational fields in a comoving reference system, motivated by cosmological applications where the physical behavior of matter is most naturally described along the medium flow. Starting from metrics admitting a three-dimensio…
The paper proves a Fourier-type integral representation for entire functions of one complex variable with arbitrary prescribed growth. It defines a class of entire functions controlled by a convex growth function h and uses the Young conjugate H to construct a countably normed space of entire functi…
This paper studies how the geometry of weak discontinuities affects absolute and quasi-absolute convergence of multidimensional Fourier series and eigenfunction expansions of elliptic operators. For functions on the two-dimensional torus weakly discontinuous along a smooth curve, it introduces quasi…
