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 investigates mean values and partial sums of complex multiplicative functions under restrictions on their values at prime powers and on weighted prime sums. Building on Halász’s analytic method, the authors analyze the associated Dirichlet series near the line Re s = 1, establishing an alt…
This paper studies continuous mappings of p-spaces and related preservation and representation problems in general topology. It establishes conditions under which images of paracompact p-spaces under open, bicompact, regularly complete, or uniformly complete mappings are weakly paracompact or p-spac…
The paper studies two problems in graph theory: finding minimum weight Hamiltonian circuits in directed and undirected graphs with integer edge or arc weights, and finding minimum edge coverings of graphs. It proposes a simple quadratic time algorithm that first constructs a long path and then inser…
This paper studies systems of nonlinear integral equations with deviating arguments under measurability, continuity, and boundedness assumptions on the kernels, deviations, and prescribed outside values. It proves compactness of the associated integral operator in a space of continuous vector functi…
The paper studies lower bounds on the complexity of finite decision procedures for recursively enumerable sets, introducing the notion of effective nonrecursiveness in terms of unbounded recursive lower estimates. It analyzes enumerations of recursively enumerable sets, giving criteria involving reg…
The paper addresses the difficulty of extending maximum likelihood estimation from discrete Gaussian measurement vectors to continuously observed Gaussian processes, where the inverse of a correlation function cannot be used directly as a matrix inverse. It approximates the correlation function by a…
This paper formulates differential games in mixed strategies for systems governed by ordinary differential equations when a value may fail to exist in pure strategies. Mixed controls are represented by time-dependent distribution functions and Lebesgue, Stieltjes measures on the players’ admissible …
This paper examines how molecular anharmonicity affects the apparent vibrational relaxation time during excitation behind shock waves and during deactivation. Using shock tube ultraviolet absorption measurements for a 10 percent oxygen and 90 percent argon mixture and for nitrogen, the authors show …
The paper studies singular integral operators in weighted Hölder spaces on smooth contours, with weights having prescribed power singularities at finitely many boundary points. It establishes compactness of commutators with Hölder coefficients and gives necessary and sufficient Fredholm type conditi…
This note studies the continuous cohomology of the topological Lie algebra of smooth vector fields on a connected compact orientable smooth manifold. Building on earlier descriptions of the cohomology of formal vector fields, it introduces and analyzes filtrations of the standard cochain complex, as…
The study investigates the temperature dependence of stimulated and unstimulated currents in polycrystalline cadmium selenide powder photoresistors between 77 and 273 K. Using sandwich-type cells measured in a cryostat after thermal resetting, the authors recorded current-voltage characteristics bef…
This paper studies the nonlinear, nonstationary impingement of antiparallel rarefied electron-proton plasma flows in a one-dimensional electrostatic model, with Boltzmann electrons and ions described by the Vlasov equation coupled to Poisson’s equation. A discrete charged-layer numerical method with…
The paper introduces the notion of a variational structure, a partially ordered Hilbert space in which every finite set has a unique upper bound minimizing a natural quadratic functional over all its upper bounds. It develops basic properties of these variational upper and lower bounds, showing that…
The paper addresses the problem of constructing the transitive closure of a directed graph more economically than the standard cubic bound, focusing on the acyclic case as a component of a broader reduction for general graphs. It partitions the vertices of an acyclic graph into ranks and expresses t…
This paper studies the distribution in arithmetic progressions of integers of the form p(p′ + a), where p and p′ are primes, for prime moduli D that may grow with the main parameter. Using Vinogradov’s method for estimating trigonometric sums over primes, together with character sums and combinatori…
The paper establishes three-cylinder type estimates for weak solutions of linear evolution quasi-elliptic equations of arbitrary order, including parabolic equations and models for transverse vibrations of elastic plates and rods. Using algebraic ellipticity and sectoriality conditions on the princi…
The paper studies when the Wallman compactification of a space coincides with the Ponomarev, Zaitsev compact extension defined via finite intersections of canonically closed sets. It introduces the notion of a seminormal space, a T1 space in which any two disjoint closed sets can be contained in dis…
This paper studies Noether properties and index formulas for integral operators on the real line whose kernels combine convolution terms with essentially bounded measurable coefficients having prescribed limiting values at infinity. A class of admissible coefficient functions is defined, and the mai…
This paper establishes conditions for localization and uniform convergence of Fourier series associated with arbitrary fundamental systems of functions of the Beltrami operator on multidimensional domains or suitable Riemannian submanifolds. Using previously developed properties of such fundamental …
The paper studies restrictions on the cardinalities of infinite extremally disconnected bicompact spaces and complete Boolean algebras, using Stone duality and cardinal invariants such as type, weight, Suslin number, and algebraic weight. It develops embedding and generation arguments for complete B…
This paper studies convergence of the method of “elastic” solutions for quasistatic boundary-value problems in a principal quasi-linear incompressible viscoelastic medium with small strains. The problem is formulated in a Hilbert space of generalized displacements, using integral identities for the …
This paper studies extremal problems for univalent functions in the class S through the structure of first variations and their associated Hilbert spaces. It introduces a positive bilinear form on variations of an extremal function, relates the second variation of linear coefficient functionals to a…
Observations of the pulsar MP 0628 were carried out at 86 and 105 MHz with a 12-channel receiving system on the Pushchino East-West radio telescope arm to study its meter-wave radio emission. The measurements show a dispersion measure of 34.36 pc cm-3, substantially larger than an earlier reported v…
This paper reports measurements of the electrical conductivity of synthetic diamond single crystals doped with aluminum and compares them with undoped crystals synthesized under similar conditions. Using a specially designed temperature-controlled contact apparatus and point-contact rectification te…
The paper studies error distributions in linear discriminant analysis for two multivariate normal populations with common covariance when the dimension is comparable to the training sample sizes. It represents the Anderson classification statistic and the associated conditional error probabilities t…
The paper constructs compact Hausdorff spaces, bicompacta, whose covering dimension and small and large inductive dimensions do not coincide. Using lexicographically ordered zero-dimensional compacta, decompositions and gluings over marked subsets of the square and the Sierpiński carpet, it gives ex…
The paper studies the topology of classes of elliptic constant coefficient matrix differential operators in the plane, focusing on the connected components of operators satisfying a positivity condition for the associated matrix pencil. It gives a necessary and sufficient criterion, expressed throug…
This paper compares the acoustic efficiency of several underwater explosive sound sources relevant to marine seismic exploration, with emphasis on how emitted energy is distributed across frequency bands rather than on total acoustic output alone. Using an exponential approximation for shock-wave pr…
This paper studies time-optimal transitions for linear controlled systems with closed bounded convex control domains and closed convex endpoint sets, extending earlier optimality criteria beyond the case of a strongly stable terminal set and without assuming nondegeneracy. It reviews extremal proces…
This paper studies the existence of nontrivial positive solutions for nonlinear boundary value problems using cone methods in Banach spaces. It develops an abstract fixed point principle for a positive completely continuous operator satisfying a cone contraction condition and a Bernstein type a prio…
This paper defines fiducial distributions for the parameters of a multivariate normal population under three standard cases: known covariance with unknown mean, unknown covariance with known mean, and both mean and covariance unknown. The definitions are formulated through equalities with invariant …
This note studies the global homological structure of minimal compacta arising in a class formulation of the multidimensional Plateau problem in compact closed Riemannian manifolds. Using Čech-Aleksandrov homology, it distinguishes several admissible classes according to the boundary and realized ho…
This paper studies minimization of convex continuous nonnegative functionals on Banach spaces that are constant on a linear subspace, with special attention to Chebyshev points for systems of affine planes. It gives conditions ensuring existence of minimizers, notably quotient reflexivity of the sub…
This note studies discreteness of the spectrum for certain non-self-adjoint operators in Hilbert space by relating them to associated symmetric and self-adjoint operators. It proves criteria showing that, under semiboundedness and compactness assumptions, discreteness of the spectral kernel or of th…
This paper investigates how Forbush decreases in galactic cosmic rays affect the cosmic-ray-produced layer of the lower ionosphere at altitudes of about 50 to 80 km. Using nighttime long-wave radio absorption observations on the Brașov to Sofia path for 25 April to 12 May 1960, together with cosmic-…
The paper addresses the observation problem for nonlinear dynamical systems, specifically the determination of unmeasured phase coordinates or initial state values from measured output signals. It proposes embedding the nonlinear system in a parameter-dependent family whose zero-parameter member is …
The paper reports the crystal structure determination of a new scheelite-related modification, Nd2WO6, using x-ray diffraction data from twinned plate crystals synthesized hydrothermally and from chloride melts. The structure is described mainly in space group I2/c, with a cell related to scheelite …
This paper examines apatite-like phases formed in the MeO, Nd2O3, SiO2 systems, where Me is Mg, Ca, or Ba, through heterovalent substitution of Nd3+ by divalent cations. Samples with nominal compositions of the type Me x Nd5-x(SiO4)3Oy were synthesized by prolonged firing at 1450 degrees C and analy…
The crystal structure of paraoxyacetophenone was investigated by X-ray diffraction in connection with comparisons to benzophenone, which has the same space group but different piezoelectric behavior. Unit-cell parameters, density measurements, and Weissenberg intensity data showed that the orthorhom…
This paper reports visual observations of the color and brightness structure of the twilight aureole near the Earth’s horizon made from the Soyuz-5 spacecraft in January 1969. The authors describe the vertical sequence of colors under cloudless, continuous cloud, and broken cloud conditions, noting …
The paper studies the large-index asymptotic behavior of eigenvalues of convolution integral operators on a finite interval when the Fourier transform of the kernel is a rational function, with particular attention to non-self-adjoint cases where the transform may be complex-valued. Using an analyti…
This paper examines the origin of the forbidden neutral oxygen lines at 6300 and 6364 Å in type I supernova spectra, focusing on the supernova in IC 4182. It argues that the observed emission can be explained by fluorescence in an expanding, initially highly ionized hydrogen envelope, analogous to t…
The paper studies separation properties of tree-like and dendroidal peripherally bicompact Hausdorff spaces, using the structure of unique ordered continua and linear hulls of closed sets. It proves that in a tree-like peripherally bicompact space any two disjoint closed sets can be separated by a d…
This paper studies boundedness criteria for singular integral and pseudodifferential operators in weighted spaces on Euclidean space. It extends earlier results of Babenko, Stein, Mikhlin, Agranovich, Plamenevskii, and others by proving weighted Lp and L2 boundedness theorems under conditions on ker…
This paper extends Stone duality to Hausdorff zero-dimensional spaces by introducing topological Boolean algebras whose topology is generated by specified ultrafilters and their complements. It defines closed topological algebras through a condition on nonprincipal algebraic components, proves conti…
This note studies linear isometries defined on subspaces of complex and real \(L^p\) spaces, with emphasis on the case \(p \ne 2\). It proves distributional lemmas showing that, except for even integer cases requiring an additional algebraic condition, an \(L^p\)-norm preserving operator on a subspa…
This paper studies the selection of a finite-difference step for numerical computation of derivatives on a uniform grid. It proves an asymptotic expansion for the central kth difference operator, showing that its leading discretization error is proportional to k times the square of the step and to t…
This paper introduces and studies auto-reducibility for mass problems, formalized as membership problems for sets of natural numbers, using oracle machines that compute each value without querying that value itself. It relates non-auto-reducibility to Kolmogorov and Loveland selection-based randomne…
This paper analyzes ray oscillations in a two-dimensional open resonator formed by a circular mirror and a plane mirror. A finite-difference mapping for successive reflected rays is derived and linearized near the axial solution, then numerical calculations are used to identify nonresonant zones ass…
This note studies uniqueness for the Cauchy problem for second-order parabolic equations with complex parameter and variable coefficients, allowing unbounded lower-order terms and solutions on a finite time interval. The argument reduces the variable-coefficient problem to a uniqueness question for …
