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 gives a proof of Hayman’s regularity theorem for coefficients of univalent functions by establishing a more general sufficient condition for regular coefficient growth. For functions normalized in the unit disk, it assumes a maximal growth condition along a radius and a square summability …
This paper reports ultrasonic measurements of longitudinal and transverse sound velocities in polycrystalline cesium chloride and sodium chloride under quasi-hydrostatic pressures up to about 100 kbar. Using a high-pressure chamber, corrected specimen-length measurements, and transit-time data refer…
This note studies an averaging procedure for nonlinear integro-differential equations with a small parameter, in which the memory term is replaced by an integral over an infinite interval and the resulting vector field is time averaged. Under continuity, Lipschitz, boundedness, and growth assumption…
This crystallographic note proves a theorem on recovering an acentric basic system of points in the Fedorov group P1 from its vector system when the vector system contains a peak of multiplicity n arising from n equal point-pair vectors, under restrictions excluding higher accidental coincidences. U…
The paper studies a second order Schrödinger type differential operator in a Hilbert space of Bochner integrable functions, with an operator valued potential depending on the real variable. Under assumptions on sectorial boundedness, Hölder continuity, growth of the operator family, and compactness …
This paper studies whether nonlinear curvature terms in the gravitational Lagrangian can remove cosmological singularities while preserving the usual Friedmann behavior at low curvature. Using field equations derived from an action of the form \(R + l^{-2}(l^2 R)^{4/3}\), the author constructs exact…
The paper proposes a general method for solving uniquely posed problems of mathematical physics by omitting different conditions, representing the resulting families of partial solutions as functional sets, and finding the original solution as their common element. It formulates both exact and far-z…
The paper studies the location of zeros of two simple classes of periodic Dirichlet functions defined by Dirichlet series with real coefficients and functional equations relating values at s and 1 minus s. Using shortened functional equations, it derives explicit classifications of possible zero con…
This paper studies estimates for the S-numbers of functions of positive linear operators in Banach spaces, including fractional powers, logarithms, iterated logarithms, and analytic semigroups. Using integral representations of fractional powers and logarithms together with standard inequalities for…
This paper gives elementary constructions of universal functions for partial recursive functions using a polynomial pairing-like map on natural numbers. It proves that any partial binary arithmetical operation satisfying three simple identities relative to this polynomial is recursively complete, an…
This paper studies an elliptic boundary value problem with two free boundaries, formulated as finding a Sobolev function constrained between two obstacles and satisfying complementary sign conditions for an elliptic operator. The analysis connects this problem with a two-sided optimal stopping game …
This paper develops a quantitative physical model for the geyser process, treating eruptions as explosive releases of superheating energy accumulated in an underground water chamber under hydrostatic pressure. The authors analyze the induction interval between eruptions using a simplified system in …
This paper studies periodic oscillations of systems that are close to essentially nonlinear differential systems with a small parameter, focusing on the special case in which the first solvability conditions for the principal amplitudes are identically satisfied for part of the arbitrary constants. …
This paper develops a theoretical treatment of nuclear magnetic relaxation in molecular crystals arising from intramolecular dipole dipole interactions when molecules undergo hindered reorientation about a fixed axis. Using the distribution of molecular orientations for random rotational jumps in a …
The note classifies nontrivial trisymmetric homogeneous Riemannian spaces with simple compact Lie groups of motions. It reformulates trisymmetry in terms of invoproducts and corresponding involutive sums of Lie algebras, proves auxiliary restrictions on the mirrors and isotropy subgroups, and reduce…
The paper studies neutrino fields in general relativity governed by the Einstein-Dirac system, with attention to solutions invariant under three-dimensional motion groups acting on two-dimensional nonisotropic transitivity surfaces. By representing spinors through associated real tensor fields, it d…
This paper constructs a broad sequence of linear positive operators defined through analytic kernels and parameter sequences, encompassing classical Bernstein, Bernstein Chlodovsky, Mirakyan, and Baskakov operators as special cases. Using Korovkin type arguments, it establishes uniform convergence o…
This paper investigates camouflet cavity formation produced by spherical explosive charges in liquids and elastoplastic media, including water, zinc chloride solution, wet clay, aluminum, cement and sand mortar, and rock salt. The authors combine pulsed radiographic measurements of cavity expansion …
The paper studies uniqueness for the Cauchy problem for linear evolution systems with variable coefficients, including systems of arbitrary type solved with respect to time and systems whose spatial part is elliptic or parabolic in the sense of Petrovsky. It develops a weighted L1 estimate in a thin…
This paper examines how the deformation force associated with motion of the Earth’s rotational pole may affect atmospheric circulation, especially the positions of the Icelandic low and Azores high. The authors derive the vertical and horizontal components of the force, argue that the vertical compo…
This paper studies differential games of approach for linear controlled systems with convex control constraints, constraints on selected phase coordinates, and terminal payoffs measuring distance to a target set. It formulates a programmed approach problem and an adjoint optimization problem in dist…
The paper studies uniform approximation on a rectangle of continuous functions of two variables by sums of one-variable functions, \(\varphi(x)+\psi(y)\). It identifies a class of supermodular-type functions for which the best approximation error is given explicitly by one quarter of the alternating…
This paper studies steepest descent type methods for solving nonlinear operator equations in real Hilbert spaces under assumptions weaker than the usual uniform positivity condition on the derivative. It analyzes continuous trajectories defined by differential equations involving the residual and it…
This paper studies the Cauchy problem for nonstrictly hyperbolic linear partial differential equations with variable coefficients in Gevrey-type classes. It formulates conditions on the real characteristic roots and uses pseudodifferential factorization, Gårding estimates, and induction on the order…
This study examines whether helium concentrations in groundwater can indicate deep tectonic faults along a deep seismic sounding profile in the Trans-Urals. Water samples, mainly from pumped wells 80 to 100 m deep, were degassed by vacuum extraction and analyzed for helium, then compared with seismi…
The paper constructs and estimates the fundamental matrix for a second order elliptic system in a three-dimensional domain with a complex spectral parameter. Under smoothness assumptions on the matrix coefficients and a negativity condition on the real parts of the roots of the characteristic equati…
This study examines the morphology of polymorphic transformations in potassium nitrate, with emphasis on the growth of the high-temperature beta phase from single-crystalline alpha-phase specimens. Using purified, well-faceted crystals and microscopic observation on a thermostated heating stage, the…
This paper studies regularization of solvable but unstable extremal problems over closed convex subsets of real Banach spaces, for quasiconvex lower semicontinuous functionals. The proposed method replaces the original minimization by the search for the least norm element in approximate level sets, …
This paper develops a linearization principle for the stability of periodic self-oscillations in infinite-dimensional dynamical systems, formulated as nonlinear partial semigroups on a Banach space. It proves an analogue of the Andronov-Witt theorem: a smooth cycle is asymptotically stable with asym…
This paper studies an inverse spectral problem for the Hill equation with a real periodic potential, focusing on what data beyond the discriminant are sufficient to determine the potential uniquely. It introduces a matrix built from the fundamental solutions over one period and proves that equality …
The paper justifies Bogolyubov’s averaging method for abstract parabolic equations in a Banach space, considering evolution equations with a rapidly varying nonlinear term and an unbounded linear operator generating an analytic semigroup. Under assumptions on fractional power spaces, compactness, di…
This note studies when realizability of propositional formulas coincides with derivability in Heyting’s intuitionistic propositional calculus, focusing on formulas with limited nesting of implication. It defines a hierarchy measuring the occurrence of implication and proves that every realizable for…
The paper studies two-dimensional integral equations on a disk whose kernels are homogeneous of order minus two and satisfy a weighted summability condition. Using complex notation, polar coordinates, and Fourier expansion in the angular variable, the equation is reduced to a diagonal system of one-…
The paper develops a method for constructing separatrix surfaces and stability regions in the phase spaces of nonlinear systems of the form consisting of a linear part plus a scalar nonlinearity. By transforming the system to diagonal coordinates and introducing two-dimensional revealing sections in…
The paper develops quotient and decomposition constructions for bicompact spaces designed to separate covering dimension, small inductive dimension, and large inductive dimension. After formulating a general scheme, it constructs families of bicompacta built from ordered compacta, Cantor sets, and m…
This paper studies the state complexity of operations on regular sets of words represented by finite automata, taking the number of states in a minimal representing automaton as the complexity measure. It gives binary alphabet examples showing that known upper bounds for union, product, and iteratio…
The paper studies continuous positive functionals that are linear with respect to Minkowski addition and nonnegative scalar multiplication on convex compact sets, equivalently on convex surfaces via support functions. It identifies these functionals with elements of the dual cone of sublinear functi…
This paper examines whether the temperatures of planetary exospheres and the solar corona are constrained by the gravitational potentials of their parent bodies. By comparing the Earth’s upper exosphere and the upper solar corona, it notes that the ratio of hydrogen particle thermal energy to gravit…
The paper develops a method for solving the Cauchy problem for the linearized Boltzmann equation and for computing space-time correlation functions of a classical one-component gas in the Boltzmann limit. Treating the collision term as an operator in a Hilbert space, it uses semiboundedness to invok…
This note studies estimation of unknown finite-dimensional regression functions in the mean of a random function with known correlation kernel. Using reproducing-kernel Hilbert spaces and extended kernels, it characterizes canonical isometries associated with the random function and derives uniforml…
This paper develops a calculation method for the stable roughness that forms after running-in during sliding elastic contact. Using the molecular-mechanical theory of friction together with a fatigue interpretation of wear, the authors argue that the stable surface state corresponds to the roughness…
This paper extends S. I. Vavilov’s theory of concentration depolarization of fluorescence by incorporating temperature and viscosity as variables affecting resonance migration of excitation energy in viscous solutions. Treating fluorescent molecules as Brownian particles, the authors derive collisio…
The paper addresses the difficulty of interpreting gas-dynamic interferograms in monochromatic light when fringe breaks, crowding, or discontinuities prevent direct fringe tracking, a problem often resolved by also recording achromatic fringes. It proposes a method for determining the integer optica…
The paper studies factorization of complex matrix polynomials satisfying the symmetry condition A(lambda) equals A*(-conjugate lambda), motivated by applications in stability, optimal control, and differential games. It gives necessary and sufficient conditions for representing such a polynomial as …
This paper gives criteria for estimating the rotation, or topological degree, of finite-dimensional vector fields that do not vanish on the boundary of a bounded domain. It proves nonnegativity results for fields in even-dimensional real spaces whose derivatives commute with matrices having no real …
Joint Franco-Soviet rocket experiments on Hayes Island in 1967 and 1968 measured temperature, winds, and diffusion in the polar upper atmosphere using artificial luminous sodium and aluminum oxide clouds released at about 120 to 174 km. Temperatures were derived from Doppler broadening of sodium res…
