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It is shown that an approach earlier used by the author for classification of closed simply connected 6-manifolds (reduction to the problem of calculating certain bordism groups) can also be applied for easily obtaining the results by Barden (1965) on classification of closed simply connected 5-manifolds. Bibliography: 11 titles.

A regular system is a Delone set in Euclidean space with a transitive group of symmetries or, in other words, the orbit of a crystallographic group. The local theory for regular systems, created by the geometric school of B. N. Delone, was aimed, in particular, to rigorously establish the “local-global-order” link, i.e., the link between the arrangement of a set around each of its points and symmetry/regularity of the set as a whole. The main result of this paper is a proof of the so-called 10R-theorem. This theorem asserts that identity of neighborhoods within a radius 10R of all points of a Delone set (in other words, an (r, R)-system) in 3D Euclidean space implies regularity of this set. The result was obtained and announced long ago independently by M. Shtogrin and the author of this paper. However, a detailed proof remains unpublished for many years. In this paper, we give a proof of the 10R-theorem. In the proof, we use some recent results of the author, which simplify the proof.

It is known that Julia sets, as a rule, have a fractal structure. In this paper, we give examples of smooth Julia sets, among them: a circle, a segment, an infinite interval, a straight line, and the complex plane. It is shown that the functions studied in the paper are chaotic on their Julia sets. The results obtained by analytical research are visualized using computer programs. The algorithms for constructing the Julia sets being considered are indicated.

In a previous paper (Funct. Anal. Appl., 3 (2015), 205–209), we defined quantum Markov states. Here we recall this definition and present a proof of the results from that paper (which are given there without proofs). We give a definition of a quantum hidden Markov state generated by a function of a quantum Markov process and show how it is related to other definitions of such states. Our definitions work for quantum Markov fields on ℤN and on graphs. We consider an example with the Cayley tree.

The main goal of this paper is to study algorithmic properties of countable linear orders by constructing effective presentations of these structures on the set of natural numbers. In 1991, C. Jockusch and R. Soare constructed a low linear order without computable presentations. Earlier, in 1989, R. Downey and M. Moses showed that each low discrete linear order has a computable copy. It is natural to ask for which order types of low presentations the existence of a computable presentation is sufficient. This question (namely, research program) was stated by R. Downey in 1998: Describe the order property P such that, for any low linear order L, P(L) implies the existence of a computable presentation of L. In this paper, we give a detailed review of the main results in this direction. These results are mostly obtained by the author or in co-authorship.

A map (S,G) is a closed Riemann surface S with embedded graph G such that S \G is the disjoint union of connected components, called faces, each of which is homeomorphic to an open disk. Tutte began a systematic study of maps in the 1960s and contemporary authors are actively developing it. In the present paper, after recalling the concept of a circular map introduced by the author and Mednykh, a relationship between bipartite maps and circular maps is demonstrated via the concept of the duality of maps. In this way an enumeration formula for the number of bipartite maps with a given number of edges is obtained. A hypermap is a map whose vertices are colored black and white in such a way that every edge connects vertices of different colors. The hypermaps are also known as dessins d’enfants (or Grothendieck’s dessins). A hypermap is self-equivalent with respect to reversing the colors of vertices if it is equivalent to the hypermap obtained by reversing the colors of its vertices. The main result of the present paper is an enumeration formula for the number of unrooted hypermaps, regardless of genus, which have n edges and are self-equivalent with respect to reversing the colors of vertices. Bibliography: 13 titles.

The quadratic Vieta formulas (x, y) ↦ (u, v) = (x + y, xy) in the complex geometry define a two-fold branched covering ℂ2 → ℂ2 ramified over the parabola u 2 = 4v. Thinking about topics considered in Arnold’s paper Topological content of the Maxwell theorem on multipole representation of spherical functions, I came to a very simple idea: in fact, these formulas describe the algebraic structure, i.e., addition and multiplication, of complex numbers. What if, instead of the field of complex numbers, we consider an arbitrary ring? Namely for an arbitrary ring A (commutative, with unity) consider the mapping Φ: A 2 → A 2 defined by the Vieta formulas (x, y) ↦ (u, v) = (x + y, xy). What kind of algebraic properties of the ring itself does this map reflect? At first, it is interesting to investigate the simplest finite rings A = ℤ m and A = ℤ k ×ℤ m . Recently, it has been very popular to consider graphs associated to rings (the zero-divisor graph, the Cayley graph, etc.). In the present paper, we study the directed graph defined by the Vieta mapping Φ.

In this paper we develop the theory of anti-compact sets we introduced earlier. We describe the class of Frechet spaces where anti-compact sets exist. They are exactly the spaces that have a countable set of continuous linear functionals. In such spaces we prove an analogue of the Hahn–Banach theorem on extension of a continuous linear functional from the original space to a space generated by some anti-compact set. We obtain an analogue of the Lyapunov theorem on convexity and compactness of the range of vector measures, which establishes convexity and a special kind of relative weak compactness of the range of an atomless vector measure with values in a Frechet space possessing an anti-compact set. Using this analogue of the Lyapunov theorem, we prove the solvability of an infinite-dimensional analogue of the problem of fair division of resources. We also obtain an analogue of the Lyapunov theorem for nonadditive analogues of measures that are vector quasi-measures valued in an infinite-dimensional Frechet space possessing an anti-compact set. In the class of Frechet spaces possessing an anti-compact set, we obtain analogues of the Krein–Milman theorem on extreme points for convex bounded sets that are not necessarily compact. A special place is occupied by analogues of the Krein–Milman theorem in terms of extreme sequences introduced in the paper (the so-called sequential analogues of the Krein–Milman theorem).

The paper deals with geometric invariants of an algebraic curve such as the minimal number of crucial values of rational functions and the minimal transcendence degree of definition fields. The main question is if the difference of these two invariants is always equal to 3 for any curve with genus g > 0. For curves defined over an algebraic number field, a positive answer is given by Belyi’s theorem. In the paper, the main question is answered in the affirmative for some other cases.

The paper is devoted to the master thesis on “information theory” which was written by the author in 1956–57. The topic was suggested by his advisor A. A. Bobrov (a student of A. Ya. Khinchin and A. N. Kolmogorov), and the thesis was written under the influence of lectures by N. I. Gavrilov (a student of I. G. Petrovskii) on the qualitative theory of differential equations, which included the statement of Birkhoff’s theorem for ergodic dynamical systems. In the thesis, the author used the concept of Shannon entropy in the study of ergodic dynamical systems f(p, t) in a separable compact metric space R with an invariant measure μ (where μ(R) = 1) and introduced the notion of the (ϵ, T)-entropy of a system as a quantitative characteristic of the degree of mixing. In the work, not only partitions of R were considered, but also partitions of the interval (−∞,∞) into subintervals of length T > 0. In particular, f(p, T) was regarded as an automorphism S of X = R, and the (ϵ, T)-entropy is essentially the e-entropy of S. But, despite some “oversights” in the definition of the (ϵ, T)-entropy and many years that have passed, the author decided to publish the corresponding chapter of the thesis in connection with the following: 1) There is a number of papers that refer to this work in the explanation of the history of the concept of Kolmogorov’s entropy. 2) Recently, B. M. Gurevich obtained new results on the ϵ-entropy hϵ(S), which show that for two ergodic automorphisms with equal finite entropies their ϵ-entropies also coincide for all ϵ, but, on the other hand, there are unexpected nonergodic automorphisms with equal finite entropies, but different ϵ-entropies for some ϵ. This shows that the concept of ϵ-entropy is of scientific value.

The present paper is devoted to graph-links with many components and consists of two parts. In the first part of the paper we classify vertices of a labeled graph according to the component they belong to. Using this classification, we construct an invariant of graph-links. This invariant shows that the labeled second Bouchet graph generates a nonrealizable graph-link. In the second part of the work we introduce the notion of an oriented graph-link. We define a writhe number for the oriented graph-link and we get an invariant of oriented graph-links, the Jones polynomial, by normalizing the Kauffman bracket with the writhe number.

The paper generalizes the results by E. Janvresse, T. de la Rue, and Y. Velenik on fluctuations in ergodic sums for the Pascal adic transformation in the case of the Lebesgue measure for a wide class of functions. In particular, we answer several questions from that paper.

Let $X,X_1,\ldots,X_n$ be independent identically distributed random variables. The paper deals with the question about the behavior of the concentration function of the random variable $\sum\limits_{k=1}^{n}X_k a_k$ according to the arithmetic structure of vectors $a_k$. Recently, the interest to this question has increased significantly due to the study of distributions of eigenvalues of random matrices. In this paper we formulate and prove multidimensional generalizations of the results Eliseeva and Zaitsev (2012). They are also the refinements of the results of Friedland and Sodin (2007) and Rudelson and Vershynin (2009)., Comment: 13 pages

This paper is devoted to the study of Abelian afi-groups. A subgroup A of an Abelian group G is called its absolute ideal if A is an ideal of any ring on G. We will call an Abelian group an afi-group if all of its absolute ideals are fully invariant subgroups. In this paper, we will describe afi-groups in the class of fully transitive torsion groups (in particular, separable torsion groups) and divisible torsion groups.

In V. D. Belousov’s papers, some properties of parastrophies were studied and some relations between parastrophies of a given quasigroup were obtained. Also some invariants of a parastrophy were found. This article continues our paper with V. V. Gushan, in which minimal sets of parastrophy systems for quasigroups of order 6 were obtained and some questions about orthogonality of parastrophies of a given quasigroup were studied as well.

The problem of characterization of integrals as linear functionals is considered in the paper. It starts from the familiar results of F. Riesz (1909) and J. Radon (1913) on integral representation of bounded linear functionals by Riemann–Stieltjes integrals on a segment and by Lebesgue integrals on a compact in \( {\mathbb{R}^n} \), respectively. After works of J. Radon, M. Frechet, and F. Hausdorff the problem of characterization of integrals as linear functionals took the particular form of the problem of extension of Radon’s theorem from \( {\mathbb{R}^n} \) to more general topological spaces with Radon measures. This problem has turned out difficult and its solution has a long and rich history. Therefore, it may be naturally called the Riesz–Radon–Frechet problem of characterization of integrals. The important stages of its solution are connected with such mathematicians as S. Banach, S. Saks, S. Kakutani, P. Halmos, E. Hewitt, R. E. Edwards, N. Bourbaki, V. K. Zakharov, A. V. Mikhalev, et al. In this paper, the Riesz–Radon–Fr´echet problem is solved for the general case of arbitrary Radon measures on Hausdorff spaces. The solution is given in the form of a general parametric theorem in terms of a new notion of the boundedness index of a functional. The theorem implies as particular cases well-known results of the indicated authors characterizing Radon integrals for various classes of Radon measures and topological spaces.

Let μ be a Borel charge (i.e., a real Borel measure) on ℝ, and let $ {P_{(y)}}(t) = \frac{y}{\pi \left( {{y^2} + {t^2}} \right)},y > 0 $ , t ∈ ℝ, denote the Poisson kernel. Bourgain proved that for a nonnegative μ and for many points t ∈ ℝ, the variation of the function $ y \mapsto \left( \mu * {P_{ {(y)}}} \right)(x) $ on (0, 1] is finite. This is true, in particular, for so-called B-points x introduced in a previous author’s paper, In the present paper, we give new descriptions of B-points which are adjusted to some applications of this notion. Bibliography: 5 titles.

The Q-index of a simple graph is the largest eigenvalue of its signless Laplacian, or Q-matrix. In our previous paper [1] we gave three lower and three upper bounds for the Q-index of nested split graphs, also known as threshold graphs. In this paper, we give another two upper bounds, which are expressed as solutions of cubic equations (in contrast to quadratics from [1]). Some computational results are also included.

In this paper, we prove some uniqueness theorems of entire functions and their derivatives that share an entire of function whose order is less than their order. The results in this paper improve those given by G. G. Gundersen and L. Z. Yang, J. P. Wang, J. M. Chang, and Y. Z. Zhu, X. M. Li and H. X. Yi, and others. Some examples are provided to show that the results in this paper are the best possible.

The aim of this paper is to study the correlation between the properties of rings and the structure of their additive groups. In this paper, all multiplications on reduced algebraically compact groups and on divisible torsion-free Abelian groups are described. Absolute Jacobson radicals and absolute nil-radicals in some classes of Abelian groups are found. Using these results, we will give a description of semisimple groups and also of groups on which every ring is a nilpotent ring (a nil-ring, a radical ring) in some concerned classes of Abelian groups.

This paper deals with an extremal problem concerning hypergraph colorings. Let k be an integer. The problem is to find the value mk(n) equal to the minimum number of edges in an n-uniform hypergraph not admitting two-colorings of the vertex set such that every edge of the hypergraph contains k vertices of each color. In this paper, we obtain the exact values of m2(5) and m2(4), and the upper bounds for m3(7) and m4(9).

For every hyperbolic toral automorphism T, the present author has defined in his previous paper some unbounded T-invariant second-order difference operators related to the so-called homoclinic group of T. These operators were considered in the space L2 with respect to the Haar measure. It is shown in the present paper that such operators give rise to transition semigroups in the space of continuous functions on the torus and generate dynamically invariant Markov processes. This leads almost immediately to a family of invariant measures for the automorphism T.Along with a short discussion, some open questions about properties of these measures are posed. Bibliography: 9 titles.

In this paper, we consider structured automata without output signals whose state sets are endowed with an algebraic structure of hypergraphs. The main result of the paper is a theorem where we obtain necessary and sufficient conditions for the possibility of defining on the state set of some automaton A a structure of a hypergraph H such that the automaton A will be the universal hypergraphic automaton.

The aim of the present (mostly expository) paper is to show the relationship of a generalization of Kazhdan’s property (T) for C*-algebras introduced in our recent paper to that of B. Bekka. It is shown that our definition coincides with Bekka’s definition for group C*-algebras of locally compact groups, whereas, in general, these definitions are distinct. Criteria for a C*-algebra to possess our property (T) are given. A number of examples of C*-algebras with and without property (T) are considered. Relations to K-theory are studied.

This paper is a follow-up to a previous paper where the logical characterization of n-ary synchronous relations due to Eilenbeig, Elgot, and Shepherdson was investigated in the case where the alphabet has infinitely many letters. Here we show that modifying one of the predicates leads to a completely different picture for infinite alphabets, though it does not change the expressive power for finite alphabets. Indeed, roughly speaking, being able to express the fact that two words end with the same symbol leads to an undecidable theory, already for the Σ2 fragment. Finally, we show that the existential fragment is decidable. Bibliography: 19 titles.

The paper is devoted to Koosis' approach to the Carleson theorem. We show that this approach also works for other related questions. The main emphasis in this paper is on the method. Bibliography: 10 titles.

This paper is a sequel to the author's papers [1–8] devoted to lower multiplicative bounds on L 1 norms and their applications. Now we give estimates for L 1 norms of exponential sums and prove the result announced in [8].

Let A be a class of Abelian groups, A ∈ A, and End(A) be the additive endomorphism group of the group A. The group A is said to be defined by its endomorphism group in the class {ie208-01} if for every group B ∈ B such that End(B) ≅ End(A) the isomorphism B ≅ A holds. The paper considers the problem of definability of a periodic Abelian group A such that End-End(A) ≅ End(A). The classes of periodical Abelian groups, of divisible Abelian groups, of reduced Abelian groups, of nonreduced Abelian groups, and of all Abelian groups are investigated in this paper.

This paper is devoted to relations between the Kurosh problem and the Shirshov height theorem. The central point and main technical tool is the identity of algebraicity. The main result of this paper is the following. Let A be a finitely generated PI-algebra and Y be a finite subset of A. For any Noetherian associative and commutative ring {ie125-01}, let any factor of R ⊗ A such that all projections of elements from Y are algebraic over π(R) be a Noetherian R-module. Then A has bounded essential height over Y. If, furthermore, Y generates A as an algebra, then A has bounded height over Y in the Shirshov sense.

This paper compares sequences of independent, mean zero random variables in a rearrangement-invariant space X on [0, 1] with sequences of disjoint copies of individual terms in the corresponding rearrangement-invariant space Z X 2 on [0, ∞). The principal results of the paper show that these sequences are equivalent in X and Z X 2 , respectively, if and only if X possesses the (so-called) Kruglov property. We also apply our technique to complement well-known results concerning the isomorphism between rearrangement-invariant spaces on [0, 1] and [0, ∞). Bibliography: 20 titles.

The present paper is one in a series of papers devoted to the classification of some classes of tame algebras up to stable category equivalence. In this paper, we study symmetric algebras (their stable categories have a structure of triangulated categories) and the simplest class of tame algebras-the class of special biserial algebras (SB-algebras). In the paper, we give a relevant version of the “diagrammatic method” and study the structure of the triangulated category “in a neighborhood” of the periodic part (with respect to Ω) of the stable category. Thus we prove the invariance of the collection of lengths of G-cycles under equivalence of stable categories (see Theorem 2.12). Then we use the invariance stated above, together with some properties of the Cartan matrix of a symmetric SB-algebra, to prove that the number of A-cycles (but not their lengths!) is also an invariant of stable equivalence. Bibliography: 8 titles.

This paper provides a method for the computation of Yoneda algebras for algebras of dihedral type. The Yoneda algebras for one infinite family of algebras of dihedral type (the family \(D(3\mathcal{Q})\)) in K. Erdmann’s notation) are computed. The minimal projective resolutions of simple modules were calculated by an original computer program implemented by one of the authors in the C++ language. The algorithm of the program is based on a diagrammatic method presented in this paper and inspired by that of D. Benson and J. Carlson.

The paper is devoted to the theory of singly generated multivalued groups. We construct new classes of such groups and find criteria that allow to check whether such a group is a coset group. For this purpose, we introduce the construction of a σ-extension of a singly generated multivalued group with Hermitian generator. This construction is based on the relation of the theory of such groups with the theory of symmetric graphs. The main result of the paper is as follows: the suggested construction of σ-extensions of singly generated bicoset multivalued groups with Hermitian generators is equivariant with respect to morphisms of graph-theoretic nature. Bibliography: 11 titles.

A new method, which enables us to compute rather efficiently the Galois group of a polynomial over ℚ or over ℤ, is presented. Reductions of this polynomial with respect to different prime modules are studied, and the information obtained is used for the calculation of the Galois group of the initial polynomial. This method uses an original modification of the Chebotarev density theorem, and it is in essence a probabilistic method. The irreducibility of the polynomial under consideration is not assumed. The appendix to this paper contains tables, which enable us to find the Galois group of polynomials of degree less than or equal to 10 as a subgroup of the symmetric group. Here the final part of the paper is published. The first part is contained in a previous issue (see Vol. 134, No. 6 (2006)). Bibliography: 10 titles.

In a paper by Cook and Reckhow (1979), it is shown that any two classical Frege systems polynomially simulate each other. The same proof does not work for intuitionistic Frege systems, since they can have nonderivable admissible rules. (The rule A/B is derivable if the formula A → B is derivable. The rule A/B is admissible if for all substitutions σ, if σ(A) is derivable, then σ(B) is derivable.) In this paper, we polynomially simulate a single admissible rule. Therefore any two intuitionistic Frege systems polynomially simulate each other. Bibliography: 20 titles.

In the paper we introduce formal calculi which are a generalization of propositional modal logics. These calculi are called fuzzy modal logics. We introduce the concept of a fuzzy Kripke model and consider a semantics of these calculi in the class of fuzzy Kripke models. The main result of the paper is the completeness theorem of a minimal fuzzy modal logic in the class of fuzzy Kripke models.

In this paper, we present a general introduction to the K-theory of C *-algebras and survey of our previous papers, where the functor N 0 from the category of von Neumann algebras to the category of Abelian groups was defined. We investigate the properties of this functor (in particular, its interrelation with the functor K 0) and point out some applications of the functor N 0 in noncommutative geometry. In addition, we recall facts of theory of C *-algebras, von Neumann algebras, and Hilbert C *-modules.

The paper is a continuation of the authors' previous paper on the topology of higher local fields. A useful class of systems of topological generators for the additive and multiplicative groups is described. Bibliography: 3 titles.

A. A. Tuganbaev UDC 512.55All rings are assumed to be associative and to have a nonzero identity element. Let A be a ring,and let M be a rightA-module. A proper ideal P ofthe ringA is said to be right primitive if P is theannihilator ofa simple rightA-module (i.e., ifthere exists a maximal right idealB ofthe ringA suchthat P is the largest ideal of A contained in B). Consequently, every maximal ideal is a right and leftprimitive ideal. A submodule N ofthe moduleM is said to be primitively pure (resp. maximally pure)ifNP = NMP for every right primitive (resp. maximal) idealP ofthe ringA. A module M is said tobe primitively divisible (resp. maximally divisible)ifM = MP for every right primitive (resp. maximal)ideal P ofthe ringA.AringA is called a right max ring ifevery nonzero rightA-module has a maximalsubmodule. Maximally pure submodules and maximally divisible modules are studied in [3,4,6,7]. In [5],right max rings with polynomial identity are described. In [10], right quasi-invariant right max rings aredescribed.The main results ofthis paper are Theorems 1 and 2.Theorem1. Let A be either a P.I. ring or a right quasi-invariant ring. Then the following conditionsare equivalent.(1) A is a regular ring.(2) All submodules of any right A-module are primitively pure.(3) All submodules of any right A-module are maximally pure.(4) All principal right ideals of the ring A are primitively pure.(5) All principal right ideals of the ring A are maximally pure.Remark1. Let A be a simple ring. It is obvious that all submodules ofanyA-module M are maximallypure and primitively pure in M. Since the ring A is not necessarily regular, Theorem 1 does not hold forarbitrary rings.Theorem2. For a P.I. ring A,the following conditions are equivalent.(1) All prime ideals of the ring A are maximal ideals,andJ(A) is a right or left t-nilpotent ideal.(2) There do not exist nonzero primitively divisible right A-modules.(3) There do not exist nonzero primitively divisible left A-modules.(4) There do not exist nonzero maximally divisible right A-modules.(5) There do not exist nonzero maximally divisible left A-modules.(6) A is a right max ring.(7) A is a left max ring.The paper also contains some other assertions on primitively (resp. maximally) pure submodulesand primitively (resp. maximally) divisible modules.The proofs of Theorems 1 and 2 are decomposed into a series of lemmas. We present the necessarynotation and definitions. For a module M,theJacobson radical of M is denoted by J(M). For a moduleM and its subset X,wedenotebyr(X) the annihilator of X. For a module M, a submodule N ofM is said to be essential if NX = 0 for every nonzero submoduleX ofthe moduleM.AringA issaid to be regular if a ∈ aAa for each element a ∈ A.AringA is said to be right quasi-invariant if

Journal of Mathematical Sciences, Vol. 112, No. 2, 2002ON ERGODICITY AND STABILITY ESTIMATES FOR SOME NONHOMOGENEOUSMARKOV CHAINSD. B. Andreev, M. A. Elesin, E. A. Krylov, A. V. Kuznetsov,andA.I.Zeifman(Vologda, Russia) UDC 519.21. IntroductionEvaluation of the rate of convergence for the ergodic continuous-time Markov chains has been the subject ofinvestigation of the number of authors(see, for example, [1{7]). There isalso a growing interest in time-nonhomogeneousMarkov chains. Such chains model a variety of queuing systems and they are also used in algorithms of simulatedannealing and some other areas. The tool of our study is the method developed in a series of papers by one of theauthors. The method is based on two basic ingredients: the logarithmic norm of a semigroup generated by a linearoperator and a similarity transformation of the reduced matrix of intensities of the considered Markov chain. In thepresent paper, we deal with continuous-time countable Markov chains. More accurate estimates give more preciseconditions for weak ergodicity and stability for the general-type intensity matrix, stability of birth and death processes,and truncations for Markov chains with bounded jumps. We improve the respective bounds of [9, Theorems 1 and 2;10, Theorem 4; 11, Theorem 3].2. General CaseT

This paper is a continuation of a paper published by the author in 1983 where the question How bad can a Banach space with approximation property be? is discussed. Some results obtained there are generalized. Bibliography: 17 titles.

The paper is an addition to the paper of Yu. I. Babenko and V. A. Zalgaller published in the same volume. It gives a condition under which the set of all vertices of several coaxial prisms inscribed in a sphere in \(\mathbb{R}_3\) has power invariants I1,...,In. A finite set in \(\mathbb{R}_3\) with 11 invariants is constructed. It is also proved that unions of prisms yield finite sets in \(\mathbb{R}_3\) with any preassigned number n of invariants with alternating signs. Bibliography: 5 titles.

In the present paper, we consider the maximum likelihood estimators of parameters of the distributions of random variables which are dependent in a certain sense. Namely, we assume that the sample forms a scheme of decomposable statistics (DS’s). The latter means that there exist independent random variables whose joint conditional distribution given their sum is fixed at some “point” coincides with the joint distribution of the sample mentioned above. DS’s form a very wide class of dependent random variables appearing both in various sections of mathematics and in other fields of science (see [2, 5, 6, 9, 16, 17] and the references therein). DS’s are most widely used in problems of mathematical statistics: in the construction of goodness-of-fit and homogeneity tests (see, e.g., [7, 8]) and in survey sampling of finite populations. DS’s automatically emerge when Neyman-type tests (see [11]) adjusted for testing hypotheses concerning the informative parameters are constructed in problems with sufficient statistics with respect to the nuisance parameter (see [16, 18–20]). The maximum likelihood method proposed by Fisher is usually used for the estimation of parameters of distributions in the classical situation, where the sample terms are jointly independent and are identically distributed with some distribution function assumed known up to a parameter. There are only a few cases (see, e.g., [15]) in which the sample terms are assumed dependent in some sense. So far as is known to the authors, the problem considered in the present paper is new and the results obtained are general, like those in the classical situation.

The objective of the paper is to find simple but rather general conditions giving the opportunity to extend the Kolmogorov theorem on the law of the iterated logarithm to the case of unbounded summands with finite variances. The results obtained in the paper include both the Kolmogorov and the Hartman-Wintner theorems. Bibliography: 11 titles.

The story of the friendship and collaboration between Vladimir Abramovich Rokhlin and the Nizhny Novgorod mathematician Dmitry Andreevich Gudkov during the last period of Rokhlin’s mathematical biography, when he worked in the topology of real algebraic varieties, in which he obtained remarkable results. The paper is based on the correspondence of 1971–1982 preserved in Gudkov’s archive containing 15 letters by V. A.Rokhlin and 8 letters by D. A. Gudkov.

The paper deals with the uniformly elliptic equation (aij(x)uxi)xj=f(x) in an unbounded domain Ω⊂ℝn and its solution u(x) that satisfies the homogeneous Neumann condition. The function f has a compact support. The domain Ω has the following structure: assume that {rm} is an increasing sequence of positive numbers, hm=rm+1−rm, and the ratio hm+1/hm lies between positive constants C1 and C2. The intersection of Ω with the spherical layer between the spheres of radius rm and rm+1 with center at the origin satisfies a certain inequality of isoperimetric type. It is shown in this paper that the set of solutions splits up into three classes: (i) the solutions for which\(\mathop {\overline {\lim } }\limits_{\left| x \right| \to \infty } u(x) = \infty \) and\(\mathop {\underline {\lim } }\limits_{\left| x \right| \to \infty } U(x) = \infty \); moreover, it is shown that these limits are attained with nearly the same speed (if C1/C2=1, then the speed is not less than the exponential one); (ii) the solutions for each of which a constant C exists such that\(\mathop {\lim }\limits_{\left| x \right| \to \infty } u(x) = C\) and u(x)−C changes its sign for large |x|; here, the convergence to C is rapid (for C1/C2=1 this convergence is not slower than the exponential one); (iii) the solutions that do not change their sign for large |x| and increase or decrease to +∞ or −∞, respectively, with low speed (for C1/C2=1 with a linear speed) (one exception is possible here: a slow convergence to a constant). Bibliography: 7 titles.

The paper continues the author's previous papers. The aim of it is to study the ellipsoids\(\Phi _{N,\Delta } \subset l_p \), which arises in problems of simple hypothesis testing. Bibliography: 11 titles.

Bifurcation diagrams of Steiner tree topologies for four boundary points are constructed in this paper. Also some properties of such diagrams for an arbitrary number of points are considered.

An association scheme is said to be T-amorphous if it is antisymmetric and any tournament obtained by an appropriate merging of its classes is doubly regular. The goal of this paper is to study basic properties of T-amorphous schemes.

Reed–Muller codes are one of the most well-studied families of codes; however, there are till open problems regarding their structure. Recently a new ring-theoretic approach has emerged that provides a rather intuitive construction of these codes. This approach is centered around the notion of basic Reed–Muller codes. It is known that basic Reed–Muller codes ℳπ(m, k) over a prime field are powers of the radical RS of a corresponding group algebra and over a nonprime field there are no such equalities, except for trivial ones. In this paper, we consider the ideals ℜSℳπ(m, k) that arise while studying the inclusions of the basic codes and radical powers.