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 eigenfunctions of first boundary value problems for elliptic equations whose coefficients degenerate at an interior point, using weighted Hilbert spaces and a normality condition near the singularity. The method removes a small ball around the degeneracy, solves the corresponding r…
This note derives trace formulas for the connected part of the resolvent of the quantum mechanical Hamiltonian for three nonrelativistic particles with pairwise interactions, under regularity and spectral assumptions on the pair potentials. Using Faddeev’s framework, Hilbert’s identity, and direct i…
This paper investigates vibrational excitation and dissociation of diatomic oxygen in atom molecule collisions in a high temperature argon gas. Using a classical mechanical treatment with an anharmonic intramolecular potential, the authors compute level to level transition and dissociation probabili…
This paper examines whether earthquake foci of widely different sizes can be treated as physically similar, given that focal dimensions range from tens of meters for weak events to hundreds or thousands of kilometers for the strongest events. Using similarity criteria derived from elastic equilibriu…
The paper addresses optimization of large-scale multiconnected systems formulated as linear programming problems with dense constraint matrices, where standard block programming or aggregation may be ineffective. It proposes reducing the constraint matrix to a special pseudodiagonal form, under cond…
This paper studies exponential stabilization of finite-dimensional linear control systems with respect to a prescribed positive definite quadratic form and a prescribed decay rate. It formulates algebraic conditions under which feedback matrices can be chosen so that the Lyapunov inequality holds wi…
This paper applies the quasioptical potential method to simple exactly solvable quantum field theory models with a fixed heavy source, in order to clarify how energy dependent, time nonlocal interactions appear in scattering. Starting from a factorized nonlocal potential, the scattering amplitude is…
This paper examines the definition of entropy in nonequilibrium statistical mechanics, focusing on the relation between Planck, Boltzmann, and Gibbs coarse-grained entropies for an isolated classical system divided into weakly interacting subsystems. It defines coarse-graining by assigning a constan…
This paper examines the use of electron-optical converters for recording soft X-ray radiation, focusing on the difficulty of reducing exposure while preserving image quality in X-ray diffraction imaging. The authors describe a four-stage converter with a thin mica input window, an internal photocath…
This note studies expansions in eigenfunctions associated with only the negative eigenvalues of a second order non-self-adjoint boundary value problem, \(y''+2A\lambda y'+B\lambda^2y=0\), \(y(0)=y(1)=0\), under the condition \(A^2-B<0\). The proof reduces the question to an auxiliary elliptic proble…
The paper proves a conjecture of V. A. Efremovich that the horocyclic pocket, defined as the universal covering of the Beltrami pseudosphere or equivalently by gluing two horocyclic domains in the Lobachevsky plane along their boundary horocycle, is not equimorphic to any surface of revolution. The …
This note extends Dzhrbashyan’s generalized Riemann Liouville type operator from a single weight function to a finite system of functions satisfying the class conditions for \(\Omega\). It defines associated coefficient sequences and kernels, then proves generalized Cauchy and Schwarz formulas for h…
This paper studies factorizations of arbitrary finite groups in terms of composition blocks, defined from the arithmetically connected classes of indices in an invariant or composition series. It introduces properly embedded systems of subgroups, invariant-index systems, and total permutability, the…
Electron paramagnetic resonance spectra of impurity Cu(II) were studied in binary oxide glasses based on phosphate, silicate, and borate formers with alkali or alkaline-earth modifiers, at room and liquid-nitrogen temperatures. The spectra are interpreted with an axial spin Hamiltonian and indicate …
This paper reports an experimental study of luminescence in uranyl crystals and frozen solutions excited by high-power ruby laser radiation, with emphasis on whether the observed emission arises from two-photon absorption and whether stimulated emission can be obtained. Luminescence spectra were rec…
This paper develops a weakly relativistic formulation of classical statistical mechanics for systems in which terms beyond order v squared over c squared may be neglected. It constructs the one-particle and Gibbs phase spaces using synchronized laboratory time, derives quasicanonical equations of mo…
A new lanthanum oxytungstate with composition 2La2O3·3WO3 was obtained as single crystals from the La2O3, WO3, NaCl system, although it had not been found in the binary La2O3, WO3 system. The crystals formed under isothermal conditions through evaporation of NaCl and partly WO3, with the largest col…
This paper proposes a method for identifying regional crustal structures of the Russian Platform by transforming anomalous geomagnetic field maps into maps of averaged horizontal gradients. The procedure calculates maximum rates of change of the magnetic field within equal map squares and uses the r…
This study examines whether the apparent differences between creep in homeopolar crystals and metals reflect bond type or the limited observation of early creep stages. Silicon single crystals were tested in uniaxial compression along the 111 direction in argon at 900 to 1300 degrees Celsius and 2 t…
This paper studies infinitesimal bendings of a surface with boundary and positive exterior curvature in a three-dimensional Riemannian space, subject to a generalized sliding boundary condition. Using isothermally conjugate coordinates, the geometric problem is reduced to boundary value problems for…
The paper formulates the design of automatic machines as an optimization problem linking reliability, utilization, productivity, and production cost. It represents unit production cost as a separable nonlinear function of reliability related adjustment durations for machine mechanisms and input mate…
The paper studies boundary-value problems for elliptic-parabolic differential equations in bounded cylinders, with an elliptic spatial operator and a finite-order time differential operator. Using localization, eigenfunction expansions, Sobolev-type spaces, and parameter-dependent elliptic estimates…
The paper studies a class of two-dimensional integral equations of the first kind on an open Lyapunov surface, with kernels of the form \(Q(g,p)/R_{gp}\), arising in mathematical physics. It introduces an auxiliary singular kernel and uses potential-theoretic representations, limiting jump relations…
This paper examines how the crystallographic orientation of single-crystal molybdenum and tungsten affects the angular and energy distributions of secondary ions scattered under low-energy ion bombardment. Using energy analysis of ions emitted from heated crystal faces while varying the azimuthal ro…
This paper studies necessary conditions for solvability and a priori estimates for pseudodifferential equations, extending earlier nonsolvability criteria of Lewy, Hörmander, Nirenberg, and Treves. It formulates conditions in terms of repeated commutators of an operator and its adjoint, and proves t…
The paper extends earlier results on a priori estimates to a broad class of second order degenerate elliptic operators in bounded domains with smooth characteristic boundary components. It formulates local normal-coordinate conditions defining alpha-ellipticity, classifies boundary components accord…
This paper formulates alternative properties of physical systems, such as locality, causality, spectrality, and energy positivity, in terms of projection operators and associated constraint equations. It applies this framework to quantum field theory, deriving projector conditions for two-field and …
This paper analytically investigates the structure of weak shock waves in thermorelaxing two-component media, such as emulsions or gases containing suspended particles, where compression produces intercomponent temperature differences and heat-exchange relaxation. Using the Mandelstam-Leontovich tre…
Bochvar analyzes comprehension axioms in the formal system K0 through the introduced notion of a measure of a kernel. For a kernel of a comprehension axiom, the paper defines maximal included and minimal covering predicates, called internal and external measures, and formulates extensions of K0 in w…
The paper studies Riemann and Hilbert type boundary value problems for a generalized Cauchy-Riemann system with a singular line, considering cases of positive and negative values of the parameter. Using integral representations of solutions in half-planes, the problems are reduced to classical conju…
This paper studies regularity conditions for properties of bases of Delta Sigma operations obtained by uniting chains of an original base, over an index space of strongly inaccessible cardinality. It defines regular and semiregular bases, proves lemmas giving sufficient closure conditions, and estab…
This paper estimates the probability of double beta decay in nuclei far from the beta stability band, where the available decay energy and number of accessible final states may be much larger than in stable nuclei. The authors derive and use expressions for two-neutrino and neutrinoless double beta …
Potassium rare-earth double tungstates KLn(WO4)2 for the lanthanide series from lanthanum to lutetium were synthesized as single crystals by crystallization from a K2WO4 and WO3 melt and examined by powder X-ray diffraction, optical goniometry, and differential thermal analysis. The study distinguis…
This paper describes a bifurcation mechanism in multidimensional dynamical systems that differs from previously studied cases involving the creation or disappearance of a single limiting element. For a smooth system with a saddle-saddle equilibrium having a zero characteristic root and finitely many…
This paper investigates the early dynamics of optical breakdown in air produced by a train of ultrashort mode-locked neodymium laser pulses. The authors use an FER-2 image-converter photochronograph with a modified laser-triggered spark-gap sweep circuit, reducing the trigger delay to about 10 to 15…
This paper examines periodic motions in a single-loop nonlinear impulse control system containing an ideal impulse element, an integrating element, a static nonlinearity, and a linear dynamic element. By deriving the point transformation over one and multiple impulse periods, the analysis formulates…
This paper studies complete regularity for stationary random processes whose spectral density has the form f(lambda) = 1/g(lambda), with g a nonnegative entire function of finite degree. It proves a necessary and sufficient criterion: integrability of |ln f(lambda)|/(1 + lambda squared) over the rea…
The paper proposes a method of incomplete factorization for certain boundary value problems in the theory of analytic functions, where coefficients on one contour admit piecewise holomorphic continuation with jumps on another contour. The approach treats the original boundary condition as partially …
The paper studies closed convex hypersurfaces in Euclidean space whose elementary symmetric function of the principal radii of curvature is prescribed as a function of the exterior normal. It proves an a priori upper estimate for every radius of normal curvature in terms of the corresponding mean ra…
This paper analyzes the absorption of laser radiation by vapor and condensate formed during rapid evaporation of an opaque solid surface. Using conservation laws, equilibrium equations of state, and estimates of radiation absorption by condensate particles and weakly ionized vapor, the authors deriv…
This paper analyzes the excitation of low-frequency nonpotential oscillations in the electron-hole plasma of a solid when an electric current flows across an external magnetic field. Using a hydrodynamic approximation with quasineutrality, Maxwell equations without displacement current, and conditio…
The paper studies a first-order Beltrami equation whose ellipticity degenerates on a simple analytic curve where the coefficient satisfies a finite-order vanishing condition for its modulus. It analyzes two geometric cases, according to whether the characteristic direction is transverse or tangent t…
This paper analyzes recombination radiation from a nondegenerate electron-hole plasma in a semiconductor plate under current-induced pinch conditions. Using a one-dimensional plate model, the authors derive expressions for the spectral and integral radiation intensities in terms of carrier distribut…
The paper studies existence and uniqueness of bounded solutions on the whole real line for nonhomogeneous linear differential equations in a Banach space with generally unbounded time-dependent operators. It develops an approximation method based on bounded solutions of associated difference equatio…
This paper studies defect indices and self-adjointness of minimal symmetric differential operators with polynomial coefficients in spaces of square-integrable functions. By representing the operators in bases of Hermite functions, the analysis reduces them to infinite Jacobi matrices with matrix coe…
The paper addresses the decomposition of direct products of irreducible representations of crystal space groups, a problem needed for applying selection rules and constructing exciton and related states in solid-state physics. It formulates a method, mainly for symmorphic space groups, for determini…
This paper examines whether finite amplitude drift waves in an inhomogeneous magnetized plasma can exhibit nonlinear excitation mechanisms absent from linear theory. Using a drift kinetic treatment with quasineutrality, the authors analyze a standing drift wave and isolate the contribution of electr…
The paper formulates a notion of normal solvability for nonlinear operator equations in Banach spaces, modeled on Hausdorff normal solvability for linear equations. It proves that if a continuously differentiable operator maps a Banach space into a reflexive Banach space and has weakly closed range,…
