On Recognition by Spectrum of Finite Simple Linear Groups over Fields of Characteristic 2

A finite group G is said to be recognizable by spectrum, i.e., by the set of element orders, if every finite group H having the same spectrum as G is isomorphic to G. We prove that the simple linear groups L _n (2^k) are recognizable by spectrum for n = 2^m ≥ 32.Original Russian Text Copyright © 2005 Vasil’ev A. V. and Grechkoseeva M. A.The authors were supported by the Russian Foundation for Basic Research (Grant 05-01-00797), the State Maintenance Program for the Leading Scientific Schools of the Russian Federation (Grant NSh-2069.2003.1), the Program “ Development of the Scientific Potential of Higher School” of the Ministry for Education of the Russian Federation (Grant 8294), the Program “Universities of Russia” (Grant UR.04.01.202), and a grant of the Presidium of the Siberian Branch of the Russian Academy of Sciences (No. 86-197).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 4, pp. 749–758, July–August, 2005.     

Dyadic Mappings and Dyadic Superparacompact Topological Groups

We introduce the notion of a dyadic superparacompactum which generalizes the classical notion of a dyadic bicompactum and give an analog of V. I. Kuz’minov and L. N. Ivanovskii’s Theorem on dyadicity of the space of a bicompact topological group for superparacompact groups. Moreover, we generalize L. S. Pontryagin’s Theorem on existence of an open bicompact subgroup in each neighborhood of unity of a locally bicompact totally disconnected topological group.Original Russian Text Copyright © 2005 Musaev D. K.__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 4, pp. 851–859, July–August, 2005.     

<Emphasis Type="Italic">n</Emphasis>-Lie Structures That Are Generated by Wronskians

We study the (k + 1)-Lie structures, k-left commutative and homotopy (k + 1)-Lie structures with multiplication generated by Wronskians and prove that the nontrivial structures of n-Lie algebras appear only in the case of small characteristic.Original Russian Text Copyright © 2005 Dzhumadil’daev A. S.__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 4, pp. 759–773, July–August, 2005.     

A Commutative Model of a Representation of the Group <Emphasis Type="Italic">O</Emphasis>(<Emphasis Type="Italic">n</Emphasis>, 1)<Superscript>X</Superscript> and a Generalized Lebesgue Measure in the Space of Distributions

For an irreducible unitary representation of an O(n, 1) current group, we consider a commutative model obtained by diagonalization with respect to a maximal unipotent subgroup. This model leads to a new measure on the space of distributions. The measure is invariant with respect to an infinite-dimensional linear symmetry group.__________Translated from Funktsional’nyi Analiz i Ego Prilozheniya, Vol. 39, No. 2, pp. 1–12, 2005Original Russian Text Copyright © by M. I. Graev and A. M. VershikThe research of the first author was supported by RFBR grant No. 04-01-00363. The research of the second author was supported by grants NSh 2251.2003.1 and RUMI-2662-ST-04.     

Integral Representations in Linearly Convex Polyhedra

We introduce the notion of mixed Levian (Levi determinant) of a system of k Hermitian and k linear forms. In terms of these Levians we obtain an integral formula for holomorphic functions in linearly convex polyhedra.Original Russian Text Copyright © 2005 Krivokolesko V. P. and Tsikh A. K.The first author was supported by a grant of the President of the Russian Federation and the State Maintenance Program for the Leading Scientific Schools of the Russian Federation (Grant NSh-1212.2003.1); the second author was supported by the Ministry for Education of the Russian Federation (St. Petersburg, Grant 02-1-138).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 3, pp. 579–593, May–June, 2005.     

The Degree Spectra of Definable Relations on Boolean Algebras

We study some questions concerning the structure of the spectra of the sets of atoms and atomless elements in a computable Boolean algebra. We prove that if the spectrum of the set of atoms contains a 1-low degree then it contains a computable degree. We show also that in a computable Boolean algebra of characteristic (1, 1, 0) whose set of atoms is computable the spectrum of the atomless ideal consists of all Π ₀ ² degrees.Original Russian Text Copyright © 2005 Semukhin P. M.The author was supported by the Russian Foundation for Basic Research (Grant 02-01-00593), the Leading Scientific Schools of the Russian Federation (Grant NSh-2112.2003.1), and the Program “Universities of Russia” (Grant UR.04.01.013).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 4, pp. 928–941, July–August, 2005.     

Concerning an Example of Paskiewich

We generalize the construction proposed by A. Paskiewich of an example of an orthonormal system which establishes the sharpness of the Men’shov-Rademacher theorem. The connection of his example with that of Men’shov is elucidated.__________Translated from Matematicheskie Zametki, vol. 78, no. 2, 2005, pp. 286–291.Original Russian Text Copyright © 2005 by A. P. Solodov.     

Elementarity and Dimensions

An alternative proof of Fedorchuk’s recent result that dim X ≤ Dg X for compact Hausdorff spaces X is given. The problem is reduced to the metric case by using the Lowenheim-Skolem theorem.__________Translated from Matematicheskie Zametki, vol. 78, no. 2, 2005, pp. 292–298.Original Russian Text Copyright © 2005 by K. P. Hart.     

Symmetries of Real Hypersurfaces in Complex 3-Space

The main result of the paper consists in the proof of the fact that for any germ of a real analytic hypersurface in complex 3-space the following alternative (dimension conjecture) takes place: either the dimension of the group of holomorphic symmetries of the germ is at most the dimension of that of a nondegenerate hyperquadric (the latter equals 15), or the group is infinite-dimensional. We also discuss mistakes found in A. Ershova’s paper.__________Translated from Matematicheskie Zametki, vol. 78, no. 2, 2005, pp. 171–179.Original Russian Text Copyright © 2005 by V. K. Beloshapka.     

About the Admissible Predicates on Admissible Sets

We study the admissible predicates, i.e., the predicates having the property that their addition to the signature of an admissible set preserves the property “to be an admissible set.” We show that the family of these predicates is much wider than the family of Δ-predicates. We also construct a family of admissible predicates of cardinality 2^ω such that the addition of an arbitrary pair of predicates of this family to the signature of an admissible set violates the admissibility of the latter as well as other examples of families of admissible predicates.Original Russian Text Copyright © 2005 Morozov A. S.The author was supported by the International Russian-German Program (Grant RFRB-DFG 01-01-04003), the Russian Science Support Foundation, and the State Maintenance Program for the Leading Scientific Schools of the Russian Federation (Grant 2112.2003.1).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 4, pp. 841–850, July–August, 2005.     

Some Spectral Properties of One Sturm-Liouville Type Problem with Discontinuous Weight

We consider a discontinuous weight Sturm-Liouville equation together with eigenparameter dependent boundary conditions and two supplementary transmission conditions at the point of discontinuity. We extend and generalize some approaches and results of the classic regular Sturm-Liouville problems to the similar problems with discontinuities. In particular, we introduce a special Hilbert space formulation in such a way that the problem under consideration can be interpreted as an eigenvalue problem for a suitable selfadjoint operator, construct the Green’s function and resolvent operator, and derive asymptotic formulas for eigenvalues and normalized eigenfunctions.Original Russian Text Copyright © 2005 Mukhtarov O. Sh. and Kadakal M.__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 4, pp. 860–875, July–August, 2005.     

Factorization Representations in the Boundary Crossing Problems for Random Walks on a Markov Chain

Let τ be some stopping time for a random walk S _n defined on transitions of a finite Markov chain and let τ(t) be the first passage time across the level t which occurs after τ. We prove a theorem that establishes a connection between the dual Laplace-Stieltjes transforms of the joint distributions of (τ, S _τ) and (τ(t), S _τ(t)). This result applies to the study of the number of crossings of a strip by sample paths of a random walk.Original Russian Text Copyright © 2005 Lotov V. I. and Orlova N. G.The authors were partially supported by the Russian Foundation for Basic Research (Grant 05-01-00810) and the Grant Council of the President of the Russian Federation (Grant NSh-2139.2003.1).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 4, pp. 833–840, July–August, 2005.     

Korn’s Inequalities for Junctions of Elastic Bodies with Thin Plates

We prove the anisotropic Korn inequalities for an elastic junction of a massive body with thin plates clamped along parts of the lateral surfaces. The distribution of the weight factors in the norms under consideration depends essentially on the disposition of the plates, the way they are clamped to the body, and their relative rigidity (as compared with the body).Original Russian Text Copyright © 2005 Nazarov S. A.The author was supported by the Russian Foundation for Basic Research (Grant 03-01-00835).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 4, pp. 876–889, July–August, 2005.     

Root Decomposition of the Ternary Malcev Algebra <Emphasis Type="Italic">M</Emphasis><Subscript>8</Subscript>

A root decomposition is constructed of the simple eight-dimensional ternary Malcev algebra M ₈. In result, M ₈ is equipped with a structure of a Z ₃-graded ternary algebra.Original Russian Text Copyright © 2005 Pozhidaev A. P.The author was supported by the Russian Science Support Foundation and partially by the Russian Foundation for Basic Research (Grant 05-01-00230).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 4, pp. 901–906, July–August, 2005.     

Justification of Dipole Approximation in the Problem of Nonlinear Wave Generation by a Submerged Sphere

Some nonlinear dipole approximation is constructed for the nonstationary problem of a solid sphere motion under a free surface. The approximation is justified in the class of analytic functions decaying at infinity.Original Russian Text Copyright © 2005 Pyatkina E. V.The author was supported by the State Maintenance Program for the Leading Scientific Schools (Grant NSh-440.2003.1) and the Russian Foundation for Basic Research (Grant 05-01-00250).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 4, pp. 907–927, July–August, 2005.     

A Generalization of the Euler Gamma Function

We define a generalized Euler gamma function Λ^β(z), where the product is taken over powers of integers rather than integers themselves. Studying the associated spectral functions and in particular the zeta function, we obtain the main properties of Λ^β(z) and its asymptotic expansion for large values of the argument.__________Translated from Funktsional’nyi Analiz i Ego Prilozheniya, Vol. 39, No. 2, pp. 87–91, 2005Original Russian Text Copyright © by M. Spreafico     

An Estimate for the <Emphasis Type="Italic">n</Emphasis>th Minimal Error of Linear Algorithms for One Problem in a Normed Vector Space

We find an estimate for the nth minimal error of linear algorithms for some problem defined in a finite-dimensional space with values in an arbitrary normed vector space.Original Russian Text Copyright © 2005 Sidorov S. P.The author was supported by the Russian Foundation for Basic Research (Grant 04-01-00060), the State Maintenance Programs for the Leading Scientific Schools of the Russian Federation (Grant 1295.2003.1), and the Program Universities of Russia (Grant 04.01.374).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 3, pp. 673–678, May–June, 2005.     

Some Relations for Double Hurwitz Numbers

We obtain new relations for Hurwitz numbers of functions with one polynomial and one arbitrary critical value. (All other critical values are supposed to be simple.) This is a straightforward generalization of our earlier results on Hurwitz numbers of functions with one polynomial critical value.__________Translated from Funktsional’nyi Analiz i Ego Prilozheniya, Vol. 39, No. 2, pp. 91–94, 2005Original Russian Text Copyright © by S. V. ShadrinSupported in part by grants RFBR-01-01-00660, RFBR-02-01-22004, and NSh-1972.2003.1.