Unknown
The paper studies differential and geometric properties of the boundary of the coefficient region for normalized univalent functions of class S. It describes extremal functions associated with singular boundary points through algebraic relations and quadratic differential equations, relates their bo…
O. V. Titov
The paper studies quasiconformal mappings of Euclidean space that arise as gradients of harmonic functions, motivated by Liouville-type rigidity results for holomorphic quasiconformal mappings. For dimension three, it proves that any nonconstant harmonic quasiconformal mapping from three-dimensional…
L. M. Lyamshev, Yu. V. Kurilkin
This paper reports experiments on nonmirror reflection of ultrasonic waves from a cadmium selenide piezosemiconductor crystal plate immersed in water, focusing on how illumination and an applied drift electric field affect amplification and absorption. Using pulsed 5 MHz ultrasound, measured polar r…
B. Sternin
The paper studies solvability of quasielliptic nonstationary differential equations and Sobolev type problems in cylinders infinite in the time direction, including settings motivated by equations such as Laplace and heat conduction without initial conditions. It introduces weighted Sobolev spaces w…
M. I. Kanovich
The paper studies how lower bounds on the complexity of finite decision procedures for enumerable sets characterize forms of universality in recursive function theory. It defines several notions of effective, strict, weak, and strong nonrecursiveness and complexity, using decision algorithms, charac…
Yu. I. Gil'derman
This paper studies two-dimensional systems of differential equations whose right-hand sides are formed from linear combinations of minima and maxima of linear functions, a class motivated by bottleneck processes and dual systems in optimal control. It shows that a pencil of lines through the origin …
V. A. Ved’min, Yu. A. Medvedev, B. M. Stepanov
This paper reports experimental measurements of the passage of 8 mm radio waves through the region produced by small TG 50-50 explosive charges. Using horn-lens antennas and oscilloscope records of the received signal envelope, the authors analyze temporal oscillations in the scattered field with a …
V. B. Dybin
The paper studies discrete and integral Wiener-Hopf operators in exceptional cases where the symbol vanishes on the unit circle or real axis. It introduces a notion of normalization for bounded linear operators with nonclosed range by changing the range space so as to obtain a Noether operator, and …
N. V. Akhvlediani
The paper analyzes the limit equilibrium of reinforced shells resting on a rigid-plastic foundation, for shells whose horizontal sections have similar polygonal or limiting curvilinear projections. Using a virtual work formulation for an assumed plastic mechanism with horizontal plastic hinges and c…
V. P. Zolotarev
The paper studies how covering dimension behaves when a topology is represented as the intersection of several zero-dimensional topologies on the same set. For metrizable spaces, it proves that dim X is at most n exactly when the topology can be expressed as the intersection of n plus 1 metrizable z…
M. A. Gintsburg
The paper studies nonstationary and stationary self-similar waves in cold plasma configurations with electric and magnetic fields that scale with radius, including cylindrical filaments, plane layers, spherical clouds, and plasma jets. By applying similarity substitutions to Maxwell’s equations and …
D. L. Berman
This note studies extended Hermite-Fejér interpolation processes formed from Chebyshev nodes with the endpoints added and one endpoint derivative condition imposed. Motivated by earlier examples of pointwise divergence, it asks whether such a weakened process can diverge at every point of the open i…
V. V. Bogorodsky, G. P. Khokhlov, B. A. Fedorov, G. V. Trepov
This study examines the dielectric properties of rock and ice systems relevant to permafrost and moraine-bearing glacier layers, with the aim of assessing their suitability for electrical and radio exploration in polar regions. Laboratory measurements were made on granite, basalt, and andesite powde…
S. S. Kabalkina, M. O. Shcherbakov, L. F. Vereshchagin
This study examines the high pressure polymorphic transformation of silver chloride and the crystal structure of the AgCl II phase, addressing discrepancies between earlier volumetric and X-ray interpretations. X-ray diffraction patterns were obtained for AgCl over 40 to 115 kbar, and for AgCl mixed…
A. V. Sychev
This note studies moduli of families of curves and higher dimensional surfaces in Euclidean space, with emphasis on surfaces passing through a point and on Hausdorff measurability. It derives an explicit modulus formula for a rotational family of two dimensional surfaces in three space, then uses it…
Yu. L. Igithanov, B. B. Kadomtsev
This paper examines the stability of a low density plasma pinch in the regime where the electron drift velocity exceeds the ion sound speed and the usual one fluid magnetohydrodynamic approximation is no longer adequate. Using ideal two fluid magnetohydrodynamic equations with the magnetic field eff…
V. S. Fedii
This paper develops sufficient conditions for hypoellipticity of linear differential operators with smooth coefficients in terms of Sobolev norm estimates and commutator bounds. It formulates conditions A, B, and C, proves that they imply local gain of regularity from \(Pu\) to \(u\), and derives hy…
V. L. Lyuboshits, M. I. Podgoretskii
This paper addresses the Gibbs paradox for ideal gases by examining cases in which the distinguishability of the gases varies continuously rather than discretely. It first treats gases that are themselves mixtures of common components and shows that the entropy of mixing is a continuous function of …
Unknown
The paper studies stability criteria for the Dirichlet and Neumann problems in three-dimensional potential theory, using a notion of stable capacity for open sets. It relates the stability of boundary value problems in a domain to the stable capacity of domains obtained by inversion from the complem…
I. Ts. Gokhberg, N. Ya. Krupnik
This note studies one-dimensional singular integral operators with piecewise continuous matrix coefficients on contours consisting of finitely many closed and open Lyapunov arcs, acting in vector-valued L2 spaces. It defines a matrix-valued symbol on an associated cylinder that accounts for jumps an…
Unknown
This paper studies the asymptotic distribution of Pearson’s chi-square statistic in multinomial schemes when the usual condition that all expected cell counts tend to infinity is not satisfied. It introduces an integral representation for characteristic functions of additively separable frequency st…
L. A. Vainshtein, M. G. Belkina
The paper presents a double reduction method for solving infinite systems of linear equations that arise when expanding unknown functions with edge or corner singularities in boundary value problems of mathematical physics. Instead of truncating all higher expansion coefficients to zero, the method …
G. A. Leonov
This paper studies absolute stability of stationary nonlinear control systems whose linear part has a critical pair of purely imaginary eigenvalues and all other eigenvalues in the left half-plane. For a scalar sector-bounded nonlinearity, it formulates conditions under which Yakubovich’s frequency …
V. P. Shunkov
This paper studies periodic and locally finite groups satisfying finiteness conditions on Sylow subgroups, especially SF-groups and S2F-groups. It gives a criterion ensuring that a maximal complete abelian 2-subgroup is invariant in an S2F-group with infinite Sylow 2-subgroups, and uses this to show…
R. M. Ganiev, V. V. Ilyukhin, Academician N. V. Belov
D. D. Sokoloff
This paper examines topological restrictions on spacetime manifolds proposed for cosmological models, including conditions related to indefinite metrics, causality, orientability, and discrete symmetry noninvariance. It argues that, by analogy with restrictions derived from CP noninvariance, CT noni…
Unknown
This paper studies Deheuvels homology for metric compact spaces with coefficients in precosheaves of Abelian groups or modules, motivated by the failure of exactness in Alexander-Cech homology. Using injective resolutions of inverse systems of chain complexes of open covers and the associated spectr…
I. M. Vilensky
The paper discusses a nonlinear ionospheric effect in which powerful radio waves heat electrons, alter the effective electron collision frequency, and thereby create artificial gradients of the refractive index in the lower ionosphere. Using Fresnel-type estimates for quasi-longitudinal propagation,…
K. M. Fishman
This note establishes necessary and sufficient conditions for pointwise convergence of sequences of continuous linear mappings between analytic spaces, formulated through equicontinuity, convergence on total sets, and uniform bounds in projective and inductive systems of Banach spaces. The general c…
B. L. Livshits
This paper investigates the origin of chaotic spiking in solid-state lasers through experiments on traveling-medium lasers using ruby, neodymium glass, and calcium tungstate doped with neodymium. By moving the active medium along the laser axis and limiting the transverse working region with diaphra…
E. P. Golubeva
This note studies representations of large integers by nondegenerate diagonal ternary quadratic forms and the distribution of integer points on the corresponding quadratic surfaces. Under a stated zero-free region assumption for real Dirichlet L-functions, it proves uniform distribution estimates fo…
V. A. Voloshin, A. A. Galkin, Yu. M. Ivanchenko, O. M. Ignat'ev, V. Yu. Tarenkov, A. O. Khrebtov
Thin-film Al, Al2O3, organic impurity, Al tunnel junctions were studied to determine how adsorbed organic molecules affect anomalous low-voltage tunnel conductivity. Naphthalene, benzophenone, and their mixture were introduced in approximately monomolecular amounts, and the resulting conductivity an…
P. P. Zabreiko, M. A. Krasnosel'skii, E. A. Livshitz
This paper studies the motion of a mass attached to a one-dimensional elastic-plastic element, modeled by a second order differential equation containing a Prager-Ishlinskii hysteresis operator. Under finiteness of the total elastic modulus and summability of the initial plastic state, the authors p…
V. F. Brekhovskikh, N. N. Rykalin, A. A. Uglov
This paper examines how gas content, impurities, and porosity in copper influence the dimensions and character of zones produced by pulsed laser irradiation. Experiments using a neodymium glass laser compared cathode, anode, black, vacuum-remelted, as-delivered, and porous copper under melting and c…
S. G. Krein, G. I. Laptev, G. A. Tsvetkova
This paper studies Hadamard well-posedness of the Cauchy problem for an abstract evolution equation with a closed linear operator in a Banach space, under the assumption that the positive half-axis is excluded from the point spectrum. It defines a maximal domain of well-posedness in terms of bounded…
G. L. Garg
This paper develops an analogue of the Kuratowski and Dugundji extension theorem for metrizable uniform spaces and uniformly continuous maps. It introduces and uses the relative large dimension of a subset, defined through Isbell’s large uniform dimension and the nearness relation, to formulate exte…
Unknown
This note establishes criteria for normal solvability, meaning closed range, of systems of singular integral operators on vector-valued \(L_2\) spaces of the form \(T=aP+bQ\), where \(P\) and \(Q\) are complementary Cauchy projection operators and \(a,b\) are continuous matrix functions on the unit …
A. P. Bulanov
This paper studies uniform best rational approximation of convex functions and functions of bounded variation on finite intervals, comparing the decay of rational approximation errors with polynomial approximation. It proves upper bounds for continuous convex functions, including an order n inverse …
A. N. Chernov, B. A. Maksimov, V. V. Ilyukhin, N. V. Belov
The paper determines the crystal structure of the monoclinic modification of potassium zirconium diorthosilicate, K2ZrSi2O7, using X-ray diffraction data, Patterson analysis, electron-density syntheses, and least-squares refinement. The structure has space group P21/b, with Zr in nearly regular octa…
Ya. A. Roitberg
This paper establishes a homeomorphism theorem for general elliptic boundary value problems in Sobolev type spaces without assuming that the boundary conditions are normal. For a properly elliptic operator with boundary expressions that may be pseudodifferential tangentially and differential normall…
G. P. Klimov
This paper formulates a fiducial approach for statistical models dominated by a common measure, defining the fiducial distribution as a limiting posterior obtained from maximum entropy priors on increasing finite-measure subsets of the parameter space. For models with sample and parameter spaces act…
G. G. Kasparov
The paper studies homotopy invariance of rational Pontryagin numbers for closed oriented smooth and PL manifolds, focusing on pairings of Hirzebruch L-polynomials with intersections of codimension one homology classes. It proves that numbers of the form obtained by evaluating L_k on such intersectio…
Y. A. Dinitz
This paper presents an exact algorithm for the maximum flow problem in a directed network with arbitrary nonnegative capacities, avoiding the rounding required by earlier methods for noncommensurable data. The method iteratively augments flow along shortest augmenting paths in the residual network, …
E. M. Lin'kov
This paper investigates long-period zero drift in seismometers as a possible manifestation of a nonlocal geophysical phenomenon. Using continuous records from a thermocompensated SVKD seismometer, spectral comparison, smoothing, and correlation analysis, the study finds stable drift spectra, weak as…
B. A. Efimov, V. M. Kuznetsov
This paper determines the number of topological types of several classes of dyadic spaces for an infinite cardinal parameter. It proves that dyadic compact spaces of weight τ have exactly 2^τ types, dyadic compact spaces of density τ have exactly 2^(2^τ) types, and dyadic spaces of density τ have ex…
Academician L. S. PONTRYAGIN
This paper strengthens earlier results on evasion in linear differential games governed by a system with compact convex control sets for the pursuer and evader, where termination occurs when the phase vector reaches a fixed subspace. It proves an evasion theorem for the case in which the orthogonal …
L. L. Buishvili, M. D. Zviadadze
This paper examines how the interaction between weakly coupled subsystems should be treated when constructing a stationary nonequilibrium density matrix. Using a spin system in constant and alternating magnetic fields as an example, it introduces the invariant part of the interaction Hamiltonian int…
F. D. Senchukov, S. Z. Shmurak
A method is proposed for determining dislocation velocities in photochemically colored ionic crystals from the deformation luminescence produced during pulsed loading. The approach relates the number of emitted light quanta to the area swept by moving dislocations, using measured or previously deter…
T. A. Sarymsakov, Ya. Kh. Kuchkarov
This paper studies ergodicity for generally noncommutative, partially semigroup families of stochastic linear operators acting on spaces of summable elements in complete topological semifields. It defines distributions, stochastic operators, ergodic and strongly ergodic families, and introduces a co…
A. V. Kuznetsov, V. Ya. Gerchiu
The paper studies superintuitionistic propositional logics through their associated pseudoboolean algebras, focusing on whether finitely axiomatizable intermediate logics are finitely approximable. It develops algebraic criteria using finite separation, pretrue formulas, Gödelian and narrow structur…