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 reports an X-ray diffraction study of crystalline iodine at room temperature under pressures up to 60 kbar, motivated by earlier evidence for pressure-induced changes in its physical properties and Bridgman’s low-pressure phase transition. Powder diffraction patterns were measured in a hi…
This paper studies the irreversible evolution of a finite fermionic dynamical system weakly coupled to a thermostat with infinitely many degrees of freedom. For a quadratic Hamiltonian model previously treated by an approximate Bogolyubov-type kinetic equation, the density matrix of the small system…
This note compares properties of constructive functions with operators acting on quasi-numbers, quasi-FL-numbers, and FR-numbers, focusing on equivalence, continuity, and uniform continuity. It shows that every constructive function has an equivalent operator of each considered type, but that the co…
The paper derives matrix elements for proper Lorentz transformations in unitary irreducible representations of the principal series, motivated by applications of noncompact symmetry groups in elementary particle classification. Using the canonical basis and representation formulas of Gelfand and Nai…
The note studies a disjunction property for propositional formulas under a constructive version of Rose’s notion of realizability, formulated through partial recursive functions and Kleene realizability after substitution of closed logical-arithmetical formulas. It proves that for any proposed reali…
This study examines the hydrothermal synthesis and crystallographic characterization of rare-earth oxytungstates with composition Ln2W2O9, where Ln is Ce, Pr, or Nd, in chloride aqueous media at high temperature and pressure. Crystals were obtained from rare-earth tungstate charges in concentrated o…
This paper develops Bayesian optimal learning algorithms for automatic systems trained by a nonideal teacher, whose output may be only a statistical estimate or evaluation rather than the exact required response. It models the system, teacher, and required behavior by conditional decision functions …
This paper presents a numerical treatment of the global propagation of semidiurnal tidal waves, specifically the M2 and S2 constituents, in the World Ocean excluding the polar basin. Starting from the Laplace tidal equations, the authors formulate a boundary value problem for the dynamic tide, discr…
The paper studies growth indicators for harmonic functions in unbounded three-dimensional domains, asking how rapidly a harmonic function may grow inside a domain while remaining bounded on the boundary and outside a prescribed set. It generalizes an earlier construction by defining a harmonic funct…
This note formulates and studies an operator-valued generalization of the classical power moment problem, motivated by structures related to Wightman field theory. For positive definite matrices of operators on tensor powers of a Hilbert space, a moment condition is expressed as the Hermiticity of a…
The paper studies finite general validity, in the sense of Medvedev, for a special class of propositional formulas built from initially negated variables using conjunction, disjunction, implication, and negation. It extends intuitionistic propositional calculus by adding a specific finitely valid ax…
A system of the form \begin{equation} x'(t)=z(x(t),t)-\int_0^tK(t,s)\psi(x(s),s)\,ds,\tag{*} \label{*} \end{equation} is considered, where $x(t)$, $z(x,t)$, $\psi(x,t)$ are $n$-dimensional vectors; $K(t,s)$ is a symmetric matrix of the $n$-th order, and $\psi_i(x,t)$ depends only on $x_i$ and $t$. C…
The work is devoted to the study of the Sturm–Liouville boundary value problem \begin{equation} \begin{gathered} y''+f(t,y,y')=0,\\ \alpha_{11}y(\alpha)+\alpha_{12}y'(\alpha)=0,\quad\alpha_{21}y(\beta)+\alpha_{22}y'(\beta)=0\end{gathered} \tag{1}, \end{equation}, which has been investigated by a num…
The paper gives a constructive justification, in a restricted formal setting, of A. A. Markov’s principle of constructive selection. It proves an algorithmic variant of P. S. Novikov’s theorem: if a normal algorithm decides a recursive property defined in the constructive arithmetical calculus and t…
This note studies a non-self-adjoint second order difference operator in l2 on the half-line, with a complex coefficient sequence and a boundary condition at the origin, as a discrete analogue of the Sturm-Liouville problem. It constructs special solutions of the associated difference equation, incl…
The paper develops a potential-based method for boundary-value problems in the electrodynamics of homogeneous gyrotropic media, illustrated for a plasma in a magnetic field with a tensor permittivity of gyrotropic form. Starting from Maxwell’s equations expressed through vector and scalar electrodyn…
This note proposes a formulation of quantum theory based on functionals associated with states, intended to encompass vectors from inequivalent representations of canonical commutation or anticommutation relations without relying on a Hilbert space framework. It defines the relevant functionals for …
A system of equations \begin{equation} dx=\sum_{i=1}^np_i(x)\,dt^i, \tag{1} \label{1} \end{equation} is considered, where $x$ and $p_i(x)$ are $(n+1)$-dimensional vectors for which the conditions of complete integrability are satisfied. It is assumed that the system \eqref{1} possesses a closed traj…
The paper studies nonlinear oscillations of thin plates while incorporating rotational inertia, addressing the non-wave character and related uniqueness difficulties of earlier plate equations. It formulates a boundary-initial value problem for the modified von Kármán-type system, defines generalize…
The paper presents a recurrent method for recalculating the characteristic polynomial of a matrix when a single column is replaced, a situation arising in numerical linear programming methods. Using the Cayley-Hamilton relation and Cramer’s formula, it derives explicit recurrence formulas for updati…
The paper extends classical dichotomy theorems for analytic, or A, sets in complete metric spaces beyond the separable case. After recalling equivalent forms of sigma-discreteness and introducing points of local sigma-discreteness, it proves that any A-set in a complete metric space is either sigma-…
This paper studies existence conditions for the inverse problem of geometrical seismics in a spherically symmetric medium with finitely many waveguides, after reducing the problem to ray propagation in a half-plane with depth-dependent velocity. It formulates necessary and sufficient conditions unde…
The paper investigates a system of three equations of strongly elliptic type, supplemented by a boundary condition for one variable and a periodicity condition for the second. This system corresponds to the problem of determining the displacements of a momentless lattice cylindrical shell from an in…
This paper addresses the problem of distinguishing etch figures produced by fission fragment tracks from those produced by dislocations in ionic crystals, where track densities may be much lower than dislocation densities and the two types of figures are visually similar. Using NaCl, KCl, LiF, and C…
The paper studies growth characteristics of functions of several positive variables that are convex with respect to the logarithms of the variables and monotone in each variable, a class including logarithmic maximum functions and related plurisubharmonic means arising in the theory of entire functi…
This paper develops a method for determining the energy spectrum of collision cascades of identical particles in a retarding medium, with attention to secondary atom-atom and electron-electron processes relevant to radiation effects in solids. The authors formulate an integral equation for the total…
The paper extends the theory of triangular representations of bounded linear operators and multiplicative representations of characteristic functions beyond the case where the operator differs from a self-adjoint or unitary operator by a compact summand. It introduces conditions based on proper chai…
This paper studies invariant solutions of a system of partial differential equations modeling liquid and gas motion in long pipelines, including turbulent and laminar gas flow and drop-liquid flow as special cases. Using Lie group classification methods, it determines the principal symmetry group fo…
This paper studies uniqueness in recovering an even function of variables x and s from its integrals over confocal ellipsoids of revolution with one focus fixed at the origin and the other moving in the hyperplane s = 0, a problem related to a linearized inverse problem for the telegraph equation. T…
This note studies inverse boundary value problems in which coefficients of the differential equation are unknown together with the solution and are determined by additional boundary conditions. For a parabolic equation with two time dependent coefficients, and for a related ordinary differential equ…
The paper studies the large time behavior of the Cauchy, Poisson problem for an ideal incompressible fluid of finite depth subjected to a time harmonic surface pressure of compact spatial support. Using a Laplace transform in time and Fourier analysis in the horizontal variables, it establishes uniq…
The paper proposes a regularization method for studying asymptotic solutions of differential equations with small parameters, aiming to separate regular and singular parameter dependence by introducing an additional independent variable defined through a regularizing function. For first order system…
This paper examines how finite plasma dimensions affect combination scattering of ultrahigh frequency electromagnetic radiation by ion acoustic oscillations. Using a plane plasma layer model, it argues that when the incident wavelength is comparable to or larger than the layer thickness, momentum co…
The paper studies averaging for systems of differential equations with a small parameter on a finite time interval, replacing the usual infinite-time mean by an average over the interval under consideration. It argues that this finite-interval averaging is applicable in cases where the infinite mean…
This note addresses the calculation of Clebsch-Gordan coefficients for symmetric irreducible representations of the groups SU_n, a problem relevant to representation theory in mathematical physics. Using recurrence relations derived from the action of infinitesimal operators, the authors first treat…
This paper studies plane deformation of orthotropic elastic viscoelastic bodies, with particular attention to fiberglass plastics whose creep behavior can be represented by power law kernels. By applying operational transforms, the viscoelastic plane problem is reduced formally to the corresponding …
This paper addresses seismic hazard assessment by supplementing maximum possible intensity zoning with estimates of the mean recurrence of shakings of specified intensity. Using earthquake catalogs for Uzbekistan from 1868 to 1964, the authors construct maps for Eastern Uzbekistan by relating maximu…
This note derives an exact optimal growth trajectory for a one-product dynamic economic model with exponentially growing labor, a Cobb-Douglas production relation, and an isoelastic utility function. Under the condition that the production elasticity equals the utility parameter, the author applies …
Magnetotelluric soundings were carried out during the drift of the Soviet station North Pole-13 to investigate the geoelectric structure beneath a shallow Arctic Ocean sector. Field components were recorded over a broad period range and interpreted using the Tikhonov-Cagniard layered-medium model, w…
The paper studies limiting distributions of normalized sums of independent, not necessarily identically distributed, random variables whose individual distributions belong to one type, or to finitely many types, under bounded scale transformations. It gives a characterization of the resulting class …
The paper extends the Bates and Damgaard semiempirical method for calculating radial integrals in atomic spectra from dipole transitions to transitions of arbitrary multipolarity. It represents radial wave functions in Coulomb form with effective principal quantum numbers and Whittaker functions, de…
The paper develops an algebraic theory of finite systems of linear inequalities over an arbitrary ordered field, avoiding topological arguments such as compactness or separation in real Euclidean space. Using finitary methods, it identifies two central results, the existence of nodal subsystems for …
