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 note studies analytic irreducible representations of the finite general linear group GL(n, Kq), defined by the absence of degenerate one-dimensional constituents upon restriction to the upper unitriangular subgroup. Using the structure of a parabolic-type subgroup Hn as a semidirect product and…
Maslov introduces semisyntopogenic spaces, a generalization of Császár’s syntopogenic spaces based on families of semitopogenic orders, and develops basic notions such as open and closed sets, connectedness, separation, and continuity. The paper constructs induced semisyntopogenic structures on spac…
This paper studies compact classes of algebraic systems in model theory, especially their behavior under enrichments, ultraproduct constructions, and product-like operations. It gives criteria for compactness in terms of elementary equivalence and ultraproduct closure, derives conditions for strict …
This paper studies a boundary value problem for a nonlinear system of second order equations of mixed type in a domain whose boundary includes an elliptic part and characteristic arcs. It develops maximum principle type lemmas and solvability results for an associated linear system with a positive d…
This paper investigates the tetragonal luminescence center of Eu3+ ions in CaF2, motivated by the need to distinguish rare-earth centers with different charge-compensation mechanisms and laser properties. Using pulsed-excitation luminescence kinetics, spectral grouping by build-up times, selection r…
The paper studies complete homeomorphisms associated with quaternionic differential equations in four-dimensional Euclidean space, focusing on equations of the form DU = aU. It proposes a method based on Hadamard’s global homeomorphism theorem: construct a solution by an integral equation, prove loc…
The paper examines whether magnetic fields can be spontaneously excited in a plasma with intense Langmuir turbulence, extending ideas known for turbulent conducting fluids. Using a kinetic treatment that separates turbulent and regular components, it derives a turbulent dielectric tensor for low-fre…
The paper addresses decision problems for finitely generated commutative semigroups with defining relations, focusing on the truth of closed first-order formulas in a signature that records multiples of generators. It replaces an earlier completeness-based universal procedure with a more constructiv…
This paper studies bounded solutions on the real line and half-line for systems of second-order ordinary differential equations of the form y'' = F(x, y, y'). Using maximum-principle arguments and iterative approximation schemes, it establishes uniqueness, existence, and a priori bounds for linear a…
This paper addresses biases in conventional determinations of the stellar luminosity function and local stellar density, especially the underestimation of low-luminosity stars and the unjustified linear extrapolation of apparent density to zero distance. It proposes a method based on assuming a Pois…
This paper presents a computational model for estimating deposition on the underlying surface of a heavy polydisperse atmospheric impurity released from an instantaneous volume source in a wind field whose velocity varies arbitrarily with height but is constant in time. The model neglects vertical t…
This paper derives a universal relation between absorption and spontaneous luminescence spectra in semiconductors under high pumping intensities, extending analogous relations previously developed for complex molecules. Assuming equilibrium carrier distributions within the conduction and valence ban…
This paper develops a perturbation theory for the Green’s function of conduction quasiparticles interacting with randomly distributed impurity particles while treating the periodic crystal-lattice field in the unperturbed Hamiltonian. It formulates averaging over impurity positions within crystal ce…
The paper addresses the conjugacy problem for braid groups, a question arising in knot theory and the theory of closed braids, previously solved only for low-order cases. It defines braid groups algebraically by generators and relations and outlines an algorithmic proof based on a sequence of lemmas…
This study examines how boron impurity affects the phosphorescence and thermoluminescence of synthetic diamonds produced from graphite in a metal solvent. After x-ray irradiation, boron-containing samples showed long-lived blue phosphorescence and a strongly intensified thermoluminescence peak near …
The paper studies dyadicity for a class of topologies on Cartesian and restricted products of topological spaces, motivated by Aleksandrov’s question on whether every countable topological group has a dyadic underlying space. It defines product topologies associated with free filters on the index se…
This paper studies when topological spaces arise as factor images of metric or generalized metric spaces, motivated by questions on the topologies induced on quotient sets by varying the metric on the preimage. It gives characterizations of generally metrizable and symmetrizable T1 spaces in terms o…
The paper studies bicompact extensions of topological spaces through inverse limits of finite projection spectra associated with canonical coverings. It defines refinements, correct refinements, lambda-strengthenings, and H-strengthenings of the spectrum of a space, then proves that bicompact semire…
This paper reports interferometric measurements of the relative dispersion of neodymium and samarium trivalent ions with respect to lanthanum ions in aqueous chloride solutions. Using the Puccianti method with a spectrograph and Jamin interferometer, and monitoring temperature differences with a dif…
This paper studies a nonlinear fourth order boundary value problem arising from the depth averaged two dimensional theory of steady ocean currents, with mixed no slip and slip type boundary conditions on solid and liquid parts of the boundary. It formulates the problem in a Sobolev space setting, es…
The paper studies the asymptotic average of composite functions F(phi(n)/n), where phi is Euler’s totient function, and addresses a refinement of an error estimate previously obtained by M. M. Tan. Assuming that F has a derivative on [0,1] satisfying a first order Lipschitz condition, the argument u…
A quantum theory is formulated for the magnetic-field-even coefficients of hopping transport in disordered lattices, with emphasis on electrical conductivity and thermopower for nonadiabatic small polarons and impurity conduction in the strong electron-phonon coupling regime. Using Kubo formulas, pe…
This paper proposes a variational principle for averaged turbulent flows, replacing Malkus’s neutral stability and maximum dissipation hypothesis with a criterion of maximum stability against the most slowly decaying disturbance. For a plane channel, the author formulates the problem through the Orr…
The paper studies the Dirichlet problem for quasilinear elliptic equations arising from the construction of a hypersurface in Euclidean space with prescribed mean curvature. It introduces a class of nonuniformly elliptic equations broad enough to include the mean curvature equation, and derives nece…
The paper studies finite difference approximations for first order symmetric systems of partial differential equations with Friedrichs-type boundary conditions. It formulates the continuous boundary-value problem, derives an a priori energy estimate under positivity assumptions on the coefficients a…
This paper extends a formal model of adaptive robots to discrete-time systems with multistep target conditions, where repeated games must eventually be won under unknown parameters of the environment, dynamics, and task. It defines sensor, motor, environment, and brain equations, then formulates suf…
This note extends Denjoy, Carleman quasianalyticity by introducing alpha-quasianalytic classes on the half-line and on finite intervals, defined through Weyl and Riemann, Liouville fractional differentiation operators. It asks which growth conditions on a sequence of bounds determine a function uniq…
The paper studies nilpotent operators that are self-adjoint with respect to an indefinite metric in Hilbert and Pontryagin spaces. It gives examples showing that nonzero nilpotent operators can be \(J\)-self-adjoint, analyzes their invariant maximal positive and negative subspaces, and proves that s…
This note studies continuous mappings of zero-dimensional bicompact spaces onto generalized Cantor discontinuums, using a local cardinal invariant called the delta-character, defined through systems of canonically closed sets. Under the generalized continuum hypothesis, it proves that if every point…
This paper examines whether ground-based observations of Pc 2 to 4 geomagnetic micropulsations can be used to estimate the size and displacement of the subsolar magnetosphere. The authors relate micropulsation periods to magnetospheric radius through a power law and determine the exponent by compari…
This note studies the characteristic classes of Lagrangian bundles associated with the Maslov and Arnold construction, viewing the Lagrangian Grassmannian as the homogeneous space U(n)/O(n). It defines geometric cycles in this space via incidence conditions on Lagrangian planes, analyzes their orien…
The paper studies the distribution of the numbers of runs of individual states and of the total number of runs in finite homogeneous Markov chains. It derives explicit formulas for selected cases where the general combinatorial expressions and asymptotic normal parameters are otherwise cumbersome, i…
This paper synthesizes laboratory measurements of the high-temperature electrical conductivity of igneous rocks for use in interpreting thermodynamic conditions in the Earth’s crust and upper mantle. Based on about 200 rock samples, mainly from the Kola Peninsula with additional basalt and comparati…
This paper studies the approximation of differentiable functions on the real line by partial sums of their Fourier Hermite expansions, for classes whose r-th derivative has a prescribed modulus of continuity. Extending a previous result for the nondifferentiable case, it derives an asymptotic formul…
The paper studies convergence of approximate methods for boundary value problems of the transport equation, especially schemes that combine simple iteration with variational acceleration. For symmetrizable one-velocity and energy problems satisfying detailed balance, the transport problem is reduced…
The paper derives sufficient instability criteria for detonation waves using a multistage model of chemical reaction zones. By analyzing the characteristic determinant for perturbations, the authors separate the short relative wavelength case into equations for individual fronts and obtain bounds on…
The paper studies a mixed boundary value problem for the wave equation in a half-space where Dirichlet data are prescribed on one part of the boundary and Neumann data on the complementary part, producing discontinuous boundary conditions along a timelike manifold. Using Fourier transform methods, p…
This paper extends several classical limit and decomposition theorems to complex distribution functions of bounded variation and their characteristic functions. It defines normal complex distributions through characteristic functions of exponential polynomial form, relates their admissibility to Shi…
The paper studies a two-point boundary value problem in an infinite spatial layer for second-order linear partial differential equations with constant coefficients, with data prescribed at two times. It introduces criteria for well-posed solvability in classes of bounded functions and functions with…
The paper formulates Einstein’s gravitational field equations as first-order nonlinear systems analogous to standard relativistic wave equations for elementary particles. Treating the metric tensor and Christoffel symbols as independent components of a single multicomponent field, it rewrites the va…
This paper studies self-adjoint operators in spaces of vector functions generated by first-order symmetric differential systems with Hermitian matrix coefficients. It establishes criteria for the defect indices and self-adjointness of the minimal operator in terms of endpoint behavior of the coeffic…
This note studies when partial sums of trigonometric Fourier series approximate periodic functions as well, in order, as the best trigonometric polynomial approximation, without the logarithmic loss known for the full class of functions with prescribed modulus of continuity. Using estimates for Four…
This note develops a topological method for studying condensing nonlinear operators in Banach spaces, extending fixed point ideas previously known for completely continuous and weakly continuous vector fields. The authors prove that a condensing operator, and also suitable homotopic families and pos…
This paper studies approximation in the mean on measurable subsets of the complex plane by functions analytic in a neighborhood of the set. For \(L^2\) approximation on arbitrary Borel sets, it gives necessary and sufficient conditions in terms of Cartan’s fine topology and thinness of the complemen…
This paper develops a perturbation theory for the Earth’s spheroidal normal oscillations, extending earlier treatments of torsional and radial modes to the more complicated sixth-order system governing coupled displacement and gravitational-potential perturbations. The authors formulate the spheroid…
The paper studies representations of partial and general recursive functions using primitive recursive functions of large range, in connection with a conjecture of Skolem. It proves that any partial recursive function can be represented, up to a correction at zero or undefinedness at zero, through t…
The paper studies eigenvectors of Hammerstein integral operators with potential Carathéodory nonlinearities in ideal Banach spaces of measurable vector functions, allowing kernels whose associated self-adjoint linear operator is positive or has finitely many negative eigenvalues. Using a variational…
This paper reports electron paramagnetic resonance measurements of conduction electrons in sodium and sodium based liquid alloys over the range from minus 200 to 300 degrees Celsius, with emphasis on the temperature and impurity dependence of the resonance linewidth. The authors measure dispersed so…
This paper discusses geological conditions associated with the occurrence of rhombohedral 3R molybdenite in the Yellowknife district of Canada, in comparison with previously reported Soviet examples. It distinguishes three molybdenite settings, pegmatites, quartz veins, and quartz-feldspar porphyry,…
