K—Bounded Sets and A—Spaces

Let(E,T)bealocallyconvexspace,asequence{xi}inEissaidtobeT-Kconvergentifeverysubsequenceof{xi}hasasubsequence{xik}suchthattheseries∑kxikisT-convergenttoanelementx∈E([1]).NotethatasequencewhichisT-KconvergentmustbeT-con-vergentto0.But,ingeneral,itisnotconversely.ThesetA(E,T)issaidtobeT-Kboundedsetifwhenever{xi}Aand{ti}isasequenceofpositivescalarswhichconvergesto0,then{tixi}isT-Kconvergent([1]).ItisclearthataT-KboundedsetisalwaysT-boundedsetbutnotconversely.ThenotionsofK-convergentand…     

Dual Representations of Convex Sets and Gâteaux Differentiability Spaces

The duality of two kinds of representations of convex sets is studied: the tangential representation of a convex body and the representations of its polar or negative polar by means of their weak^* exposed points. The equivalence of the representations is proved and a condition for their validity is obtained for individual sets (the case of arbitrary locally convex space) and for classes of sets (the case of Gâteaux differentiability locally convex space). Properties of Gâteaux differentiability locally convex spaces are studied and some examples of such spaces are given.

     

Large Sets and Overlarge Sets of Triangle-Decomposition

There are six types of triangles:undirected triangle,cyclic triangle,transitive triangle,mixed-1triangle,mixed-2 triangle and mixed-3 triangle.The triangle-decompositions for the six types of triangles havealready been solved.For the first three types of triangles,their large sets have already been solved,and theiroverlarge sets have been investigated.In this paper,we establish the spectrum of LT_i(v,λ),OLT_i(v)(i=1,2),and give the existence of LT_3(v,λ)and OLT_3(v,λ)with λ even.     

Almost αg-Closed Functions and Separation Axioms

We introduce a new class of functions called almost g-closed and use the functions to improve several preservation theorems of normality and regularity and also their generalizations. The main result of the paper is that normality and weak normality are preserved under almost g-closed continuous surjections.     

Approximatively Compact Sets in Asymmetric Efimov–Stechkin Spaces and Convexity of Almost Suns

Mathematical Notes -     

Realizing Quasiordered Sets by Subspaces of ‘Continuum-Like’ Spaces

Given an ordered set E and a topological space X, we say that E can be realized within X if there is an injection j from E into the class of (homeomorphism classes of) subspaces of X such that, for x, y in E, x y if and only if j(x) is homeomorphically embeddable into j(y). It is known, for instance, that transfinite induction demonstrates that every partially-ordered set of cardinality c (and some larger ones) can be realized within the real line. We explore aspects of the realizability problem, indicating, in particular, how to weaken the hypothesis on E from partial- to quasi-order, and seeking to isolate the characteristics of the real line that are relevant here.     

Teichmüller Spaces and Function Spaces

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Fuzzy S-Regular Spaces and S-Almost Regular Spaces

ＦｕｚｚｙＳＲｅｇｕｌａｒＳｐａｃｅｓａｎｄＳＡｌｍｏｓｔＲｅｇｕｌａｒＳｐａｃｅｓＦａｎｇＪｉｎｍｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＭａｔｈｅｍａｔｉｃｓ，ＯｃｅａｎＵｎｉｖｅｒｓｉｔｙｏｆＱｉｎｇｄａｏ，Ｑｉｎｇｄａｏ，２６６０...     

Characterizations of K-smooth Spaces and K-strongly Smooth Spaces

Some necessary and sufficient conditions for a Banach space to be K-smooth or Kstrongly smooth are obtained.     

Selection Principles and Sierpinski Sets

We show that a set of real numbers is a Sierpinski set if, and only if, it satisfies a selection property similar to the familiar Menger property.     

Kolmogorov＇s ε-Entropy of Bounded Sets in Discrete Spaces and Attractors of Dissipative Lattice Systems

We obtain an estimate of the upper bound for Kolmogorov＇s ε-entropy for the bounded sets with small ＂tail＂ in discrete spaces, then we present a sufficient condition for the existence of a global attractor for dissipative lattice systems in a reflexive Banach discrete space and establish an upper bound of Kolmogorov＇s ε-entropy of the global attractor for lattice systems.     

Regular Spaces and Hyper-spaces

We are concerned with the construction of regular spaces and hyper-spaces,and the characterization of continuous linear operators in such spaces.     

On Strong π-Regularity and π-Regularity

Rowen showed that the 2 by 2 full matrix rings over strongly π-regular rings need not be strongly π-regular. In this note we extend Rowen's method to the n by n full matrix rings. Moreover we show that the n by n full matrix rings over π-regular rings need not be π-regular.     

Groups with π-maximal and π-layer maximal conditions

By analogy with π-minimal, π-layer minimal, primary minimal, and layer minimal conditions, similar maximal conditions are introduced and studied. Translated fromMatematicheskie Zametki, Vol. 68, No. 2, pp. 311–320, August, 2000.     

Function Spaces on τ-Corson Compacta and Tightness of Polyadic Spaces

We apply the general theory of -Corson Compact spaces to remove an unnecessary hypothesis of zero-dimensionality from a theorem on polyadic spaces of tightness . In particular, we prove that polyadic spaces of countable tightness are Uniform Eberlein compact spaces.     

Generalized Skyrme model for π- and π′-mesons

On the basis of a generalization of the Skyrme model for pseudoscalar -mesons and their radial excitations (-mesons), soliton (skyrmion) solutions are studied. It is shown that taking -mesons into account allows one to solve the problem of the soliton stability. The skyrmion energy, angular moment, and axial coupling constant are computed in this configuration.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 189, pp. 10–14, 1991.The authors would like to thank A. A. Andrianov for discussions and for his constant interest in this work, and V. N. Popov and P. P. Kulish for the possibility of its publishing in these proceedings.     

Siegel’s Lemma and Sum-Distinct Sets

Let L(x)=a ₁ x ₁+a ₂ x ₂+???+a _n x _n , n≥2, be a linear form with integer coefficients a ₁,a ₂,…,a _n which are not all zero. A basic problem is to determine nonzero integer vectors x such that L(x)=0, and the maximum norm ‖x‖ is relatively small compared with the size of the coefficients a ₁,a ₂,…,a _n . The main result of this paper asserts that there exist linearly independent vectors x ₁,…,x _n?1∈? ⁿ such that L(x _i )=0, i=1,…,n?1, and $$\|{\mathbf{x}}_{1}\|\cdots\|{\mathbf{x}}_{n-1}\|<\frac{\|{\mathbf{a}}\|}{\sigma_{n}},$$ where a=(a ₁,a ₂,…,a _n ) and $$\sigma_{n}=\frac{2}{\pi}\int_{0}^{\infty}\left(\frac{\sin t}{t}\right)^{n}\,dt.$$ This result also implies a new lower bound on the greatest element of a sum-distinct set of positive integers (Erdös–Moser problem). The main tools are the Minkowski theorem on successive minima and the Busemann theorem from convex geometry.