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Hilbert–Pólya Operators in Krein Spaces Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 V. V. Kapustin
We construct some class of selfadjoint operators in the Krein spaces consisting of functions on the straight line \( \{\operatorname{Re}s=\frac{1}{2}\} \). Each of these operators is a rank-one perturbation of a selfadjoint operator in the corresponding Hilbert space and has eigenvalues complex numbers of the form \( \frac{1}{s(1-s)} \), where \( s \) ranges over the set of nontrivial zeros of the
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On the Levi Class of the Quasivariety of Right-Orderable Groups Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 A. V. Zenkov
We show that the Levi class of the quasivariety of right-orderable groups strictly includes this quasivariety.
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Estimates of Alexandrov’s $ n $ -Width of the Compact Set of $ C^{\infty} $ -Smooth Functions on a Finite Segment Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 V. N. Belykh
We obtain two-sided estimates for Alexandrov’s \( n \)-width of the compact set of infinitely smooth functions boundedly embedded into the space of continuous functions on a finite segment.
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Structure of the Variety of Alternative Algebras with the Lie-Nilpotency Identity of Degree 5 Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 S. V. Pchelintsev
We construct an additive basis for a relatively free alternative algebra of Lie-nilpotent degree 5, describe the associative center and core of this algebra, and find the T-generators of the full center. Also, we give some asymptotic estimate for the codimension of the T-ideal generated by a commutator of degree 5 in a free alternative algebra, and find a finite-dimensional superalgebra that generates
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Topological Properties of Mappings with Finite Distortion on Carnot Groups Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 D. V. Isangulova
We prove that every mapping with finite distortion on a Carnot group is open and discrete provided that it is quasilight and the distortion coefficient is integrable. Also, we estimate the Hausdorff dimension of the preimages of points for mappings on a Carnot group with a bounded multiplicity function and summable distortion coefficient. Furthermore, we give some example showing that the obtained
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The Injectivity Radius and Shortest Arcs of the Oblate Ellipsoid of Revolution Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 V. N. Berestovskii, A. Mustafa
We found the geodesics, shortest arcs, cut loci, and injectivity radius of any oblate ellipsoid of revolution in three-dimensional Euclidean space.
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On the Approximative Properties of Fourier Series in Laguerre–Sobolev Polynomials Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 R. M. Gadzhimirzaev
Considering the approximation of a function \( f \) from a Sobolev space by the partial sums of Fourier series in a system of Sobolev orthogonal polynomials generated by classical Laguerre polynomials, we obtain an estimate for the convergence rate of the partial sums to \( f \).
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Admissible Inference Rules of Modal WCP-Logics Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 V. V. Rimatskiy
We study admissible rules for the extensions of the modal logics S4 and GL with the weak co-covering property and describe some explicit independent basis for the admissible rules of these logics. The resulting basis consists of an infinite sequence of rules in compact and simple form.
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Two Series of Components of the Moduli Space of Semistable Reflexive Rank 2 Sheaves on the Projective Space Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 A. A. Kytmanov, N. N. Osipov, S. A. Tikhomirov
We construct two new infinite series of irreducible components of the moduli space of semistable nonlocally free reflexive rank 2 sheaves on the three-dimensional complex projective space. In the first series the sheaves have an even first Chern class, and in the second series they have an odd one, while the second and third Chern classes can be expressed as polynomials of a special form in three integer
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Kolmogorov Equations for Degenerate Ornstein–Uhlenbeck Operators Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 V. I. Bogachev, S. V. Shaposhnikov
We consider Kolmogorov operators with constant diffusion matrices and linear drifts, i.e., Ornstein–Uhlenbeck operators, and show that all solutions to the corresponding stationary Fokker–Planck–Kolmogorov equations (including signed solutions) are invariant measures for the generated semigroups. This also gives a relatively explicit description of all solutions.
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Birman–Hilden Bundles. I Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 A. V. Malyutin
A topological fibered space is a Birman–Hilden space whenever in each isotopic pair of its fiber-preserving (taking each fiber to a fiber) self-homeomorphisms the homeomorphisms are also fiber-isotopic (isotopic through fiber-preserving homeomorphisms). We present a series of sufficient conditions for a fiber bundle over the circle to be a Birman–Hilden space.
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On the Separability of Abelian Subgroups of the Fundamental Groups of Graphs of Groups. II Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 E. V. Sokolov
Consider the fundamental group \( {\mathfrak{G}} \) of an arbitrary graph of groups and some root class \( {\mathcal{C}} \) of groups, i.e., a class containing a nontrivial group and closed under subgroups, extensions, and unrestricted direct products of the form \( \prod_{y\in Y}X_{y} \), where \( X,Y\in{\mathcal{C}} \) and \( X_{y} \) is an isomorphic copy of \( X \) for each \( y\in Y \). We provide
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Oriented Rotatability Exponents of Solutions to Homogeneous Autonomous Linear Differential Systems Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 A. Kh. Stash
We fully study the oriented rotatability exponents of solutions to homogeneous autonomous linear differential systems and establish that the strong and weak oriented rotatability exponents coincide for each solution to an autonomous system of differential equations. We also show that the spectrum of this exponent (i.e., the set of values of nonzero solutions) is naturally determined by the number-theoretic
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A Spectral Criterion for Power-Law Convergence Rate in the Ergodic Theorem for $ {��}^{d} $ and $ {��}^{d} $ Actions Sib. Math. J. (IF 0.5) Pub Date : 2024-02-07 A. G. Kachurovskii, I. V. Podvigin, V. È. Todikov, A. Zh. Khakimbaev
We prove the equivalence of the power-law convergence rate in the \( L_{2} \)-norm of ergodic averages for \( {}^{d} \) and \( {}^{d} \) actions and the same power-law estimate for the spectral measure of symmetric \( d \)-dimensional parallelepipeds: for the degrees that are roots of some special symmetric polynomial in \( d \) variables. Particularly, all possible range of power-law rates is
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Boolean Valued Analysis of Banach Spaces Sib. Math. J. (IF 0.5) Pub Date : 2024-01-01
Abstract We implement the Boolean valued analysis of Banach spaces. The realizations of Banach spaces in a Boolean valued universe are lattice normed spaces. We present the basic techniques of studying these objects as well as the Boolean valued approach to injective Banach lattices.
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Admissibility and Unification in the Modal Logics Related to S4.2 Sib. Math. J. (IF 0.5) Pub Date : 2024-01-01
Abstract We study unification and admissibility for an infinite class of modal logics. Conditions superimposed to these logics are to be decidable, Kripke complete, and generated by the classes of rooted frames possessing the greatest clusters of states (in particular, these logics extend modal logic S4.2). Given such logic \( L \) and each formula \( \alpha \) unifiable in \( L \) , we construct a unifier
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The Riesz–Zygmund Sums of Fourier–Chebyshev Rational Integral Operators and Their Approximation Properties Sib. Math. J. (IF 0.5) Pub Date : 2024-01-01
Abstract Studying the approximation properties of a certain Riesz–Zygmund sum of Fourier–Chebyshev rational integral operators with constraints on the number of geometrically distinct poles, we obtain an integral expression of the operators. We find upper bounds for pointwise and uniform approximations to the function \( |x|^{s} \) with \( s\in(0,2) \) on the segment \( [-1,1] \) , an asymptotic expression
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The Quasi-Two-Dimensional Coefficient Inverse Problem for the Wave Equation in a Weakly Horizontally Inhomogeneous Medium with Memory Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 Z. A. Akhmatov, Zh. D. Totieva
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On the Virtual Potency of Automorphism Groups and Split Extensions Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 D. N. Azarov
We obtain some sufficient conditions for potency and virtual potency for automorphism groups and the split extensions of some groups. In particular, considering a finitely generated group \( G \) residually \( p \)-finite for every prime \( p \), we prove that each split extension of \( G \) by a torsion-free potent group is a potent group, and if the abelianization rank of \( G \) is at most 2 then
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$ BV $ -Spaces and the Bounded Composition Operators of $ BV $ -Functions on Carnot Groups Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 D. A. Sboev
Under study are the homeomorphisms that induce the bounded composition operators of \( BV \)-functions on Carnot groups. We characterize continuous \( BV_{\operatorname{loc}} \)-mappings on Carnot groups in terms of the variation on integral lines and estimate the variation of the \( BV \)-derivative of the composition of a \( C^{1} \)-function and a continuous \( BV_{\operatorname{loc}} \)-mapping
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On the Irreducible Carpets of Additive Subgroups of Type $ F_{4} $ Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 A. O. Likhacheva
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On the Existence of Two Affine-Equivalent Frameworks with Prescribed Edge Lengths in Euclidean $ d $ -Space Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 V. A. Alexandrov
We study the existence of the two affine-equivalent bar-and-joint frameworks in Euclidean \( d \)-space which have some prescribed combinatorial structure and edge lengths. We show that the existence problem is always solvable theoretically and explain why to propose a practical algorithm for solving the problem is impossible.
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Finite Time Stabilization to Zero and Exponential Stability of Quasilinear Hyperbolic Systems Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 N. A. Lyul’ko
We consider the asymptotic properties of solutions to the mixed problems for the quasilinear nonautonomous first-order hyperbolic systems with two variables in the case of smoothing boundary conditions. We prove that all smooth solutions to the problem for a decoupled hyperbolic system stabilize to zero in finite time independently of the initial data. If the hyperbolic system is coupled then we show
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Graphical Limits of Quasimeromorphic Mappings and Distortion of the Characteristic of Tetrads Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 V. V. Aseev
We fully describe the form of the graphical limit of a sequence of \( K \)-quasimeromorphic mappings of a domain \( D \) in \( \overline{R^{n}} \) which take each of its values at \( N \) distinct points at most. For the family of all \( K \)-quasimeromorphic mappings of \( \overline{R^{n}} \) onto itself taking each value at \( N \) points at most we establish the presence of a common estimate for
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On Locally Finite Subgroups in $ \operatorname{Lim}(N) $ Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 N. M. Suchkov, A. A. Shlepkin
Let \( G \) be the group of all limited permutations of the naturals \( N \). We prove that every countable locally finite group is isomorphic to a subgroup in \( G \).
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The Myshkis 3/2 Theorem and Its Generalizations Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 V. V. Malygina
We discuss the well-known Myshkis result on the stability of nonautonomous first-order delay differential equations, providing an extension to the general differential equations with aftereffect, and make comparison with available results.
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Classes of Noncontact Mappings of Carnot Groups and Metric Properties Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 M. B. Karmanova
We study the metric properties of level surfaces for classes of smooth noncontact mappings from arbitrary Carnot groups into two-step ones with some constraints on the dimensions of horizontal subbundles and the subbundles corresponding to degree 2 fields. We calculate the Hausdorff dimension of the level surfaces with respect to the sub-Riemannian quasimetric and derive an analytical relation between
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Openness and Discreteness of Mappings of Finite Distortion on Carnot Groups Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 S. G. Basalaev, S. K. Vodopyanov
We prove that a mapping of finite distortion \( f:\Omega\to 𝔾 \) in a domain \( \Omega \) of an \( H \)-type Carnot group \( 𝔾 \) is continuous, open, and discrete provided that the distortion function \( K(x) \) of \( f \) belongs to \( L_{p,\operatorname{loc}}(\Omega) \) for some \( p>\nu-1 \). In fact, the proof is suitable for each Carnot group provided it has a \( \nu \)-harmonic function of
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$ E $ -Rings and Quotient Divisible Abelian Groups Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 M. N. Zonov, E. A. Timoshenko
Under study are the relations between \( E \)-rings and quotient divisible abelian groups. We obtain a criterion for the quotient divisibility of the additive group of an \( E \)-ring and give a negative solution to the Bowshell and Schultz problem about the quasidecompositions of \( E \)-rings.
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On the Existence of Radially Symmetric Solutions for the $ p $ -Laplace Equation with Strong Gradient Nonlinearities Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 Ar. S. Tersenov
We consider the Dirichlet problem for the \( p \)-Laplace equation in presence of a gradient not satisfying the Bernstein–Nagumo type condition. We define some class of gradient nonlinearities, for which we prove the existence of a radially symmetric solution with a Hölder continuous derivative.
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The Minimal Number of Generating Involutions Whose Product Is 1 for the Groups $ PSL_{3}(2^{m}) $ and $ PSU_{3}(q^{2}) $ Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 R. I. Gvozdev, Ya. N. Nuzhin
Considering the groups \( PSL_{3}(2^{m}) \) and \( PSU_{3}(q^{2}) \), we find the minimal number of generating involutions whose product is 1. This number is 7 for \( PSU_{3}(3^{2}) \) and 5 or 6 in the remaining cases.
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Almost Convergent 0-1-Sequences and Primes Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 N. N. Avdeev
We study 0-1-sequences and establish the connection between the values of the upper and lower Sucheston functional on such sequence and the set of all possible divisors of the elements in the sequence support. If the union of the sets of all simple divisors of the elements in a 0-1-sequence support is finite then the sequence is almost convergent to zero. We study the 0-1-sequences whose support consists
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Regularization of a Distribution Holomorphic in a Parameter Sib. Math. J. (IF 0.5) Pub Date : 2023-11-24 A. L. Pavlov
We give sufficient conditions for regularizing a distribution of the form \( a(\sigma,\lambda)f(\lambda) \), where \( f(\lambda) \) is a distribution holomorphic in the parameter \( \lambda \), while \( a(\sigma,\lambda) \) is an infinitely differentiable function of \( \sigma \) outside some closed set \( N \) with power singularities of derivatives on \( N \) and holomorphic in \( \lambda \).
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Locally Convex Spaces with All Archimedean Cones Closed Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 A. E. Gutman, I. A. Emelianenkov
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On the Existence of Hereditarily $ G $ -Permutable Subgroups in Exceptional Groups $ G $ of Lie Type Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 A. A. Galt, V. N. Tyutyanov
A subgroup \( A \) of a group \( G \) is \( G \)-permutable in \( G \) if for every subgroup \( B\leq G \) there exists \( x\in G \) such that \( AB^{x}=B^{x}A \). A subgroup \( A \) is hereditarily \( G \)-permutable in \( G \) if \( A \) is \( E \)-permutable in every subgroup \( E \) of \( G \) which includes \( A \). The Kourovka Notebook has Problem 17.112(b): Which finite nonabelian simple groups
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Continuity of the Mappings with Finite Distortion of the Sobolev Class $ W^{1}_{\nu,\operatorname{loc}} $ on Carnot Groups Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 S. K. Vodopyanov
We prove the continuity of the mappings with finite distortion of the Sobolev class \( W^{1}_{\nu,\operatorname{loc}} \) on Carnot groups and establish that these mappings are \( \mathcal{P} \)-differentiable almost everywhere and have the Luzin \( \mathcal{N} \)-property.
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On Well-Posedness of the Cauchy Problem for Pseudohyperbolic Equations in Weighted Sobolev Spaces Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 L. N. Bondar, G. V. Demidenko
We consider a class of strictly pseudohyperbolic equations and establish some solvability conditions of the Cauchy problem in the class of weighted Sobolev spaces. We also prove the uniqueness of solutions and obtain some estimates.
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On Some Properties of Semi-Hamiltonian Systems Arising in the Problem of Integrable Geodesic Flows on the Two-Dimensional Torus Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 S. V. Agapov, Zh. Sh. Fakhriddinov
Bialy and Mironov demonstrated in a recent series of works that the search for polynomial first integrals of a geodesic flow on the 2-torus reduces to the search for solutions to a system of quasilinear equations which is semi-Hamiltonian. We study the various properties of this system.
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Infinitesimal Sliding Bendings of Compact Surfaces and Euler’s Conjecture Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 I. Kh. Sabitov
We give some historical information about Euler’s conjecture on the rigidity of compact surfaces as well as the available results related to its proof. We thoroughly describe an approach to the conjecture by infinitesimal bendings in the case when the deformation of the surface is considered in the class of sliding bendings. We prove that Euler’s conjecture is true for the surfaces of revolution of
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Harnack’s Inequality for Harmonic Functions on Stratified Sets Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 N S. Dairbekov, O. M. Penkin, D. V. Savasteev
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On Extension of Multilinear Operators and Homogeneous Polynomials in Vector Lattices Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 Z. A. Kusraeva
We establish the existence of a simultaneous extension from a majorizing sublattice in the classes of regular multilinear operators and regular homogeneous polynomials on vector lattices. By simultaneous extension from a sublattice we mean a right inverse of the restriction operator to this sublattice which is an order continuous lattice homomorphism. The main theorems generalize some earlier results
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Invariant Algebraic Manifolds for the Rucklidge Model of Double Convection Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 M. V. Demina, D. O. Ilyukhin
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On Solvability of Parabolic Equations with Essentially Nonlinear Differential-Difference Operators Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 O. V. Solonukha
We consider the first mixed boundary value problem for a nonlinear differential-difference parabolic equation. We give some sufficient conditions for the nonlinear differential-difference operator to be radially continuous and coercive as well as has the property of (V,W)-semibounded variation (in this case we provide the algebraic condition of strong ellipticity for an essentially nonlinear differential-difference
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Quasi-Invariant and Invariant Functionals and Measures on Systems of Topological Loops and Quasigroups Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 S. V. Ludkovsky
Under study are the left-invariant, right-invariant, and quasi-invariant functionals and measures on topological loops and quasigroups. We also address the relations between topologies and measures on loops, the left-invariant, right-invariant, and quasi-invariant functionals and measures on locally connected as well as profinite loops and quasigroups. Moreover, we inspect how the quasi-invariant measures
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Sobolev’s Worldline and Memes Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 S. S. Kutateladze
This is a brief overview of the worldline and memes of Sergei Sobolev (1908–1989), a cofounder of distribution theory.
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Generalization of the ABC Theorem on Locally Nilpotent Derivations Sib. Math. J. (IF 0.5) Pub Date : 2023-09-26 V. V. Kikteva
We obtain a generalization of the ABC Theorem on locally nilpotent derivations to the case of the polynomials with \( m \) monomials such that each variable is included just in a sole monomial. As applications of this result we provide some construction of rigid and semirigid algebras and describe the Makar-Limanov invariant of algebras of a special form.
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Decompositions in Semirings Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 Ts. Ch.-D. Batueva, M. V. Schwidefsky
We prove that each element of a complete atomic \( l \)-semiring has a canonical decomposition. We also find some sufficient conditions for the decomposition to be unique that are expressed by first-order sentences. As a corollary, we obtain a theorem of Avgustinovich–Frid which claims that each factorial language has the unique canonical decomposition.
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Hölder Continuity of the Traces of Sobolev Functions to Hypersurfaces in Carnot Groups and the $ \mathcal{P} $ -Differentiability of Sobolev Mappings Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 S. G. Basalaev, S. K. Vodopyanov
We study the behavior of Sobolev functions and mappings on the Carnot groups with the left invariant sub-Riemannian metric. We obtain some sufficient conditions for a Sobolev function to be locally Hölder continuous (in the Carnot–Carathéodory metric) on almost every hypersurface of a given foliation. As an application of these results we show that a quasimonotone contact mapping of class \( W^{1,\nu}
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Knot as a Complete Invariant of the Diffeomorphism of Surfaces with Three Periodic Orbits Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 D. A. Baranov, E. S. Kosolapov, O. V. Pochinka
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An Inverse Problem of Recovering the Variable Order of the Derivative in a Fractional Diffusion Equation Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 A. N. Artyushin
We consider a fractional diffusion equation with variable space-dependent order of the derivative in a bounded multidimensional domain. The initial data are homogeneous and the right-hand side and its time derivative satisfy some monotonicity conditions. Addressing the inverse problem with final overdetermination, we establish the uniqueness of a solution as well as some necessary and sufficient solvability
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On the Rational Integrals of Two-Dimensional Natural Systems Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 S. V. Agapov, M. M. Tursunov
We study a natural mechanical system having an additional first integral in the form of a function rational in momenta. One of the authors has proved recently that if the configuration space of the system is the two-dimensional torus; then, provided that the potential is analytic, the existence of a rational integral with analytic periodic coefficients and small degrees of the numerator and denominator
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On Extension of a Regular Automorphism Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 D. V. Lytkina, V. D. Mazurov
Given a regular automorphism of a normal abelian subgroup of a periodic group, we find some sufficient conditions for the possibility of extending the automorphism to the whole group.
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Well-Formedness vs Weak Well-Formedness Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 V. V. Przyjalkowski
The literature contains two definitions of well formed varieties in weighted projective spaces. By the first, a variety is well formed if its intersection with the singular locus of the ambient weighted projective space has codimension at least 2. By the second, a variety is well formed if it does not include a singular stratum of the ambient weighted projective space in codimension 1. We show that
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Finite Groups with Some $ S $ -Permutably Embedded Subgroups Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 Z. Qiu, G. Chen, J. Liu
A subgroup \( H \) of a finite group \( G \) is \( S \)-permutably embedded in \( G \) if each Sylow subgroup of \( H \) is a Sylow subgroup of some \( S \)-permutable subgroup of \( G \). In this paper, we study the structure of the finite groups some of whose subgroups are \( S \)-permutably embedded. Our results improve and generalize many available results.
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Lower Semilattices of Separable Congruences of Numbered Algebras Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 N. Kh. Kasymov, A. S. Morozov
Under study are the closure properties for various classes of separable congruences (in particular, of equivalences) of numbered algebras on the natural numbers under the upper and lower bounds in the lattice of congruences. We show that the class of all positive congruences forms a sublattice whereas the classes of negative, computably separable, and separable congruences form a lower but not always
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Metric Space Mappings Connected with Sobolev-Type Function Classes Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 A. S. Romanov
We study some properties of the metric space mappings connected with the Sobolev-type function classes \( M^{1}_{p}(X,d,\mu) \).
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Poisson Total Boundedness and Total Oscillability of Solutions to Systems of Differential Equations Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 K. S. Lapin
This is a continuation of the author’s study of some special form of boundedness of solutions to systems of differential equations, namely, their Poisson boundedness. The latter concept generalizes the classical boundedness of a solution and means that there are a ball in the phase space and countably many disjoint intervals on the time half-axis such that the sequence of right endpoints of the intervals
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On Extension of Positive Multilinear Operators Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 A. A. Gelieva, Z. A. Kusraeva
Using the linearization of positive multilinear operators by means of the Fremlin tensor product of vector lattices makes it possible to show that a multilinear operator from the Cartesian product of majorizing subspaces of vector lattices to Dedekind complete vector lattice admits extension to a positive multilinear operator on the Cartesian product of the ambient vector lattices. We establish that
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Distances between Maximal Monotone Operators Sib. Math. J. (IF 0.5) Pub Date : 2023-07-24 A. A. Tolstonogov
We introduce a series of distances between maximal monotone operators and study their properties. As applications, we consider the existence of solutions to evolutionary inclusions with maximal monotone operators.