K—强凸与局部K一致光滑空间

本文引进Ｋ－强凸与局部Ｋ一致光ａｎａｃｈ空间，讨论了局部Ｋ一致凸。Ｋ－强凸。中点局部Ｋ一致凸、Ｋ－严格凸之间的关系，证明了Ｋ－强凸与Ｋ－强光滑、局部Ｋ一致凸与局部Ｋ一致光滑是对偶概念，导出了局部Ｋ一致光滑空间是Ｋ－强光滑的。     

Orlicz-Sobolev空间的k一致凸性

k一致凸性是Banach空间的重要几何属性,结合Orlicz空间和Sobolev空间的技巧给出了Orlicz-Sobolev空间关于Luxemburg范数的k一致凸性成立的充要条件.     

局部k-一致凸空间的对偶空间

本文证明了若Ｂａｎａｃｈ空间Ｘ是局部ｋ-一致凸的，则对每个ｘ∈Ｓ（Ｘ），ｆ∈Σ（ｘ）是Ｘ^*的ｋ－强光滑点，并得到局部ｋ－一致凸空间的几个性质．     

局部凸空间P-自反下的中点局部k-一致凸性(光滑性)

在局部凸空间已有的中点局部kk-一致凸性和中点局部k-一致光滑性这一对对偶概念的基础上,证明了中点局部kk-一致凸性与中点局部(k+1)-一致凸性的关系,给出了在P-自反的条件下它们之间的等价对偶定理.     

非常极凸空间的推广及其对偶概念

本文研究了k非常极凸和k非常极光滑空间的问题.利用Banach空间理论的方法,证明了k非常极凸空间和k非常极光滑空间是一对对偶概念,并且k非常极凸空间(k非常极光滑空间)是严格介于k一致极凸空间和k非常凸空间(k一致极光滑空间和k非常光滑空间)之间的一类新的Banach空间,得到了k非常极凸空间和k非常极光滑空间的若干等价刻画以及k非常极凸(k非常极光滑性)与其它凸性(光滑性)之间的蕴涵关系,推广了非常极凸空间和非常极光滑空间,完善了k非常极凸空间及其对偶空间的研究.     

关于k-致凸性和k-致光滑性的几点注记

设X为Banach空间,记U(X)={x∈X:‖x‖≤1}。V.I.Istratescu引入了下面两个概念。Banach空间Z叫做k一致凸的,如果对每个ε>0,存在δ(ε)>0,当x₁,…,x_k,y₁,…,y_k为U(X)中的元素.本文证明上述k一致凸性等价于一致凸性,并且X为k一致光滑的当且仅当X为一致光滑的,因此这两个概念都不是新的概念。     

关于k极凸空间的几点注记

本文证明了k极凸是严格介于冼军和胡长松的k极凸性和何仁义的k极凸性之间的一种新凸性.利用k极凸空间的概念,得到了k极凸的性质以及与其它凸性之间的蕴涵关系,完善了k极光滑及其对偶空间的研究.     

若干近凸空间和近光滑空间的注记

指出了关于近-强凸(近-非常凸、局部近-一致光滑)的两种不同形式的定义实质上是等价的,从而统一了有关文献中的一些结果.     

局部和中点局部K一致光滑空间

本文引进（弱）中点局部K一致光滑空间的概念,并讨论了局部K一致光滑空间和中点局部K一致光滑空间的性质以及它们和一些已知K-光滑空间之间的关系.     

关于ω-强凸空间的一点注记

本文研究了关于ω-强凸空间和ω-强光滑空间的问题.利用Banach理论的方法,证明了ω-强凸空间和ω-强光滑空间是一对对偶概念,并讨论了ω-强光滑性与其它光滑性之间的关系,用切片统一刻画了ω-强凸空间与ω-强光滑空间的特征,完善了ω-强凸空间及其对偶空间的研究.     

k-super-strongly convex and k-super-strongly smooth Banach spaces

In this paper, we introduce two types of new Banach spaces: k-super-strongly convex spaces and k-super-strongly smooth spaces. It is proved that these two notions are dual. We also prove that the class of k-super-strongly convexifiable spaces is strictly between locally k-uniformly rotund spaces and k-strongly convex spaces, and obtain some necessary and sufficient conditions of k-super-strongly convex space (respectively k-super-strongly smooth space). Also, for each k?2, it is shown that there exists a k-super-strongly convex (respectively k-super-strongly smooth) space which is not (k−1)-super-strongly convex (respectively (k−1)-super-strongly smooth) space.     

On Two-sided Locally Convex H*-algebras

We introduce (left, right, two-sided) locally convex H*-algebras, and we give conditions under which an one-sided locally convex H*-algebra turns to be a two-sided one (actually, a locally convex H*-algebra). We also give an example of a proper right locally convex H*-algebra with a (right) involution, which is not a left involution and an example of a proper two-sided locally convex H*-algebra, which is not a locally convex H*-algebra. Moreover, we connect (via an Arens-Michael decomposition) a two-sided locally m-convex H*-algebra with the classical (Banach) two-sided H*-algebras. Further, we present conditions so that the left, right involutions be continuous, and we see when a twosided locally convex H*-algebra is a dual one. Finally, we present some properties of invariant ideals which play an important rôle in structure theory of two-sided locally convex H*-algebras.     

Locally convex quotient lattice cones

Walter Roth has investigated certain equivalence relations on locally convex cones in [W. Roth, Locally convex quotient cones, J. Convex Anal. 18, No. 4, 903–913 (2011)] which give rise to the definition of a locally convex quotient cone. In this paper, we investigate some special equivalence relations on a locally convex lattice cone by which the locally convex quotient cone becomes a lattice. In the case of a locally convex solid Riesz space, this reduces to the known concept of locally convex solid quotient Riesz space. We prove that the strict inductive limit of locally convex lattice cones is a locally convex lattice cone. We also study the concept of locally convex complete quotient lattice cones.     

On convexity properties of ψ-direct sums of Banach spaces

The ψ-direct sum of Banach spaces is strictly convex (respectively, uniformly convex, locally uniformly convex, uniformly convex in every direction) if each of the Banach spaces are strictly convex (respectively, uniformly convex, locally uniformly convex, uniformly convex in every direction) and the corresponding ψ-norm is strictly convex.     

一类局部凸空间及其映照特征

称局部凸空间（E,(?)0）为WCM空间若对于任何弱于(?)0的局部凸拓扑(?),（E,(?)）与（E,(?)0）具相同的弱紧圆凸集.本文研究了WCM空间的存在性及其与其他类型局部凸空间之间的关系,还给出了WCM空间的一种映照特征.     

Dual Representations of Convex Sets and Gateaux 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.     

Hypercyclic operators on quasi-Mazur spaces

Modifying the method of Ansari, we give some criteria for hypercyclicity of quasi-Mazur spaces. They can be applied to judging hypercyclicity of non-complete and non-metrizable locally convex spaces. For some special locally convex spaces, for example, Köthe (LF)-sequence spaces and countable inductive limits of quasi-Mazur spaces, we investigate their hypercyclicity. As we see, bounded biorthogonal systems play an important role in the construction of Ansari. Moreover, we obtain characteristic conditions respectively for locally convex spaces having bounded sequences with dense linear spans and for locally convex spaces having bounded absorbing sets, which are useful in judging the existence of bounded biorthogonal systems.     

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.

     

On complemented subspaces of sums and products of Banach spaces

It is proved that there exist complemented subspaces of countable topological products (locally convex direct sums) of Banach spaces which cannot be represented as topological products (locally convex direct sums) of Banach spaces.

     

Some results on non-semireflexive spaces

In this paper we prove a result similar to a generalization due to M. Valdivia (4) of a theorem of V.L. Klee (1), in the context of real locally convex spaces which possess a metrizable locally convex topology coarser than the Mackey topology. In particular, we obtain some criteria of reflexivity for metrizable locally convex spaces. A particular case works for complex spaces.We thank Prof. Valdivia for his help and constant orientation This work follows from his suggestions.