The weakly neighborly polyhedral maps on the 2-manifold with euler characteristic −1

A weakly neighborly polyhedral map (w.n.p. map) is a two-dimensional cell-complex which decomposes a closed 2-manifold without boundary, such that for every two vertices there is a 2-cell containing them. We prove that there are just four w.n.p. maps with Euler characteristic –1 and we describe them.     

On weakly neighborly polyhedral maps of arbitrary genus

A weakly neighborly polyhedral map (w.n.p. map) is a 2-dimensional cell-complex which decomposes a closed 2-manifold without boundary, such that for every two vertices there is a 2-cell containing them. We lay the foundation for an investigation of the w.n.p. maps of arbitrary genus. In particular we find all the w.n.p. maps of genus 0, we prove that for everyg> the number of w.n.p. maps of genusg (orientable or not) is finite, and we find an upper bound for the number of vertices in a w.n.p. map of genusg>0. This upper bound grows as (4g(^2/3) wheng→∞.     

Continuity of Pseudo-differential Operators Associated with the Bessel Operator in Some Gevrey Spaces

The pseudo-differential operator (p.d.o) h w , a associated with the Bessel operator d 2 / dx 2 + (1 m 4 w 2 )/4 x 2 involving the symbol a ( x , y ) whose derivatives satisfy certain growth conditions depending on some increasing sequences, is studied on certain Gevrey spaces (ultradifferentiable function spaces). It is shown that the operator h w , a is a continuous linear map of one Gevrey space into another Gevrey space. A special p.d.o. called the Gevrey-Hankel potential is defined and some of its properties are investigated. A variant H w , a of h w , a is also discussed.     

Common periodic trajectories of interval maps

We prove that for any continuous piecewise monotone or smooth interval map f and any subset of the set of periods of periodic trajectories of f, there is another map such that the set of periods of periodic trajectories common for f and , which is denoted by , coincides with . At the same time, for each integer , there exists a continuous map f such that for any map if is an infinite set. Dedicated to Vladimir Igorevich Arnold     

Some proximity and sensitivity results in quadratic integer programming

We show that for any optimal solution for a given separable quadratic integer programming problem there exist an optimal solution for its continuous relaxation such that wheren is the number of variables and(A) is the largest absolute subdeterminant of the integer constraint matrixA. Also for any feasible solutionz, which is not optimal for the separable quadratic integer programming problem, there exists a feasible solution having greater objective function value and with . We further prove, under some additional assumptions, that the distance between a pair of optimal solutions to an integer quadratic programming problem with right hand side vectorsb andb, respectively, depends linearly on b–b₁. Finally the validity of all the results for nonseparable mixed-integer quadratic programs is established. The proximity results obtained in this paper are extensions of some of the results described in Cook et al. (1986) for linear integer programming.This research was partially supported by Natural Sciences and Engineering Research Council of Canada Grant 5-83998.     

On the Center of Continuous Maps of Dendrites

The structure and the depth of the center of a continuous map of a dendrite with a closed countable set of branch points of a finite order are studied. It is proved that the center of that map coincides with the closure of the set of periodic points. It is shown also that for an arbitrary natural number n S 2 there are the dendrite X n with a closed countable set of branch points of a finite order and the continuous map f n : X n M X n with n as the depth of the center.     

环F_(p~k)+uF_(p~k)+u~2F_(p~k)上的常循环码和循环码

记环R=F_(p~k)+uF_(p~k)+u~2F_(p~k),定义了一个从R~n到F_(p~k)~(2np~k)的Gray映射.利用Gray映射的性质,研究了环R上(1-u~2)-循环码和循环码.证明了环R上码是(1-u~2)-循环码当且仅当它的Gray象是F_(p~k)上的准循环码.当(n,p)=1时,证明了环R上的长为n的线性循环码的Gray象置换等价于域F_(p~k)上的线性准循环码.     

Local conditions for the existence of the spectral shift function

Let U_o, U₁ be unitary operators in a Hilbert space. If the operator U_x — U_o is nuclear, then (as M. G. Krein established) there exists a function on the unit circle , satisfying the equality for all functions with derivative from the Wiener class. M. Sh. Rirman and M. G. Krein proved that the function n is connected with the scattering matrix S for the pair U_o, U₁ by In this paper (1) and (2) are proved under more general (local) conditions on the pair U_o, U₁. Under these conditions we investigate some properties of the function n and describe the class of functions , which are admissible in (1). Applications to differential operators are given.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 73, pp. 102–117, 1977.     

论附属于某种连续映像的不等式及其在纤维空间中的应用

<正> §1. 设 X,Y 为拓扑空间,又设 f:X→Y 为连续映像.J.H.C.Whitehead 证明 X,Y 为 CW 丛而 f 能导出基本群及上同调群间的同模对应时,f 为同伦对等映像.映像 f 是否存在,不仅与 X,Y 的基本群及上同调群的构造有关,而与 X,Y 内在的几何结构有密切的关系.连续照像 f 导出 X,Y 之间上同调群的准同模对应 f,那末 f 能与某些准同模对应相交换,由此 J.H.C.Whitehead 指出正则准同模的观念.由[4]可知正则同模论供应我们许多同伦不变量,它们是直接可以计算的东西,并且对于 X,Y 间连续映像的分类问题,应该有密切的关系.     

Marcinkiewicz integral on weighted Hardy spaces

In this paper we give sufficient conditions to imply the $H^{1}_{w}-L^{1}_{w}$ boundedness of the Marcinkiewicz integral operator $\mu_\Omega$, where w is a Muckenhoupt weight. We also prove that, under the stronger condition $\Omega \in {\rm Lip}_\alpha$, the operator $\mu_\Omega$ is bounded from $H^{p}_{w}$ to $L^{p}_{w}$ for $\max\{n/(n+1/2), n/(n+\alpha)\}$ < p < 1.     

GIRSANOV＇S THEOREM ON ABSTRACT WIENER SPACES

ＴＨＥＰＥＲＴＵＲＢＡＴＩＯＮＴＨＥＯＲＹＦＯＲＴＨＥＳＵＭＭＡＢＩＬＩＴＹＯＦＳＥＬＦＡＤＪＯＩＮＴＯＰＥＲＡＴＯＲＳＣ．Ｗ．ＬＥＵＮＧＭａｎｕｓｃｒｉｐｔｒｅｃｅｉｖｅｄＮｏｖｅｍｂｅｒ１４，１９９４．ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍ...     

关于Haar 酉元的一个注记

设M 是一个Ⅱ₁ 型因子, τ 是M 的正规的、忠实的迹态, U ∈ M 是一个Haar 酉元, p ∈ M是一个投影, τ (p) = (1/n) (n > 3, n ∈ Z), p 和U 自由. 我们用初等方法证明了若pUp = wh 是pUp 的极分解, 则w 也是一个Haar 酉元且w 和h 是自由的. 我们还给出了pUp 的矩的刻画.     

Basic boundary value problems of thermoelasticity for anisotropic bodies with cuts. I

The three-dimensional problems of the mathematical theory of thermoelasticity are considered for homogeneous anisotropic bodies with cuts. It is assumed that the two-dimensional surface of a cut is a smooth manifold of an arbitrary configuration with a smooth boundary. The existence and uniqueness theorems for boundary value problems of statics and pseudo-oscillations are proved in the Besov ( ) and Bessel-potential ( ) spaces by means of the classical potential methods and the theory of pseudodifferential equations on manifolds with boundary. Using the embedding theorems, it is proved that the solutions of the considered problems are Hölder continuous. It is shown that the displacement vector and the temperature distribution function areC -regular with any exponent <1/2.This paper consists of two parts. In this part all the principal results are formulated. The forthcoming second part will deal with the auxiliary results and proofs.     

Maximal inequalities for a continuous semimartingale

Let X =( X t ) t S 0 be a continuous semimartingale given by d X t = f ( t ) w ( X t )d d M ¢ t + f ( t ) σ ( X t )d M t , X 0 =0, where M =( M t , F t ) t S 0 is a continuous local martingale starting at zero with quadratic variation d M ¢ and f ( t ) is a positive, bounded continuous function on [0, X ), and w , σ both are continuous on R and σ ( x )>0 if x p 0. Denote X 𝜏 * =sup 0 h t h 𝜏 | X t | and J t = Z 0 t f ( s ) } ( X s )d d M ¢ s ( t S 0) for a nonnegative continuous function } . If w ( x ) h 0 ( x S 0) and K 1 | x | n σ 2 ( x ) h | w ( x )| h K 2 | x | n σ 2 ( x ) ( x ] R , n >0) with two fixed constants K 2 S K 1 >0, then under suitable conditions for } we show that the maximal inequalities c p , n log 1 n +1 (1+ J 𝜏 ) p h Á X 𝜏 * Á p h C p , n log 1 n +1 (1+ J 𝜏 ) p (0< p < n +1) hold for all stopping times 𝜏 .     

Propriété de stabilité de la fonction extrémale relative

Nous donnons une caractérisation des domaines DX pour lesquels la fonction extrémale relative ^*(,E,D) a la propriété de stabilité pour tout ED, i.e. lim _k^*(,E,D _k )=^*(,E,D), ED. Ensuite, nous étudions la relation entre cette propriété et les enveloppes pluripolaires. Nous concluons par quelques remarques sur la propriété de stabilité lim _k^*(,E _k ,D)=^*(,E,D).     

RC *-fields

It is stated that if a Boolean family W of valuation rings of a field F satisfies the block approximation property (BAP) and a global analog of the Hensel-Rychlick property (THR), in which case F, W is called an RC^*-field, then F is regularly closed with respect to the family W (The-orem 1). It is proved that every pair F, W, where W is a weakly Boolean family of valuation rings of a field F, is embedded in the RC^*-field F₀, W₀ in such a manner that R₀ R₀ F, R₀ W₀ is a continuous map, W₀ is homeomorphic over W to a given Boolean space, and R₀ is a superstructure of R₀ F for every R₀ W₀ (Theorem 2).Translated fromAlgebra i Logika, Vol. 33, No. 4, pp. 367–386, July-August, 1994.     

Degeneracy of holomorphic curves in surfaces

Let X be a complex projective algebraic manifold of dimension 2 and let D1,…,Du be distinct irreducible divisors on X such that no three of them share a common point. Let f: C→X\(U1≤i≤uDi) be a holomorphic map. Assume that u≥4 and that there exist positive integers n1,…,nu, c such that ninj(Di.Dj) = c for all pairs i, j. Then f is algebraically degenerate, i.e. its image is contained in an algebraic curve on X.     

Perfect powers from the sums of terms of linear recurrences

Let Gi= {Gi n1 n=0 (i = 1;2 ;m; m 2) be linear recursive se- quences of order ki 2 andGn 2 Z. Further let K >1 be a fixed real number and S = s 2 Z : s = p e 11p ev v ; ei 2 N , wherepi"s are fixed primes. In this paper, under some restrictions, we prove that, if m P i=1 G (i) n i = sw q holds for positive in- tegers w 2; q; n1; n2; nm with n1 > K max (n2; nm), then q tegers w 2; q; n1; n2; nm with n1 > K max (n2; nm), then q...     

Equivalent composition operators

If is an analytic function taking the unit disk into itself then the composition operatorC can be defined on the Hardy spaceH ^p(D) byC (f)=fo. In this work, the question of when two of these operators are equivalent in some sense is studied. In some cases, it turns out that the only equivalences are those that are induced by an invertible composition operator. However, other cases are exhibited in which there are equivalences that are not induced by an invertible composition operator.Much of this work comes from the author's thesis, written under the direction of Carl C. Cowen at Purdue University. Final preparations were accomplished with the help of a faculty development grant from the University of Tampa.     

Definability of Completely Decomposable Torsion-Free Abelian Groups by Groups of Homomorphisms

Let C be an Abelian group. An Abelian group A in some class of Abelian groups is said to be _C H-definable in the class if, for any group B\in , it follows from the existence of an isomorphism Hom(C,A) Hom(C,B) that there is an isomorphism A B. If every group in is _C H-definable in , then the class is called an _C H-class. In the paper, conditions are studied under which a class of completely decomposable torsion-free Abelian groups is a _C H-class, where C is a completely decomposable torsion-free Abelian group.