局部域上的局部Hardy空间

文献［１］，［２］，［３］中讨论了Ｒ^ｎ上的局部Ｈａｒｄｙ空间，并利用乘子定理证明了ｈ_ｐ（Ｒ^ｎ）＝Ｆ_p.2⁰（Ｒ^ｎ）．本文利用Ｃｈｅｂｙｓｈｅｖ等式及正则函数的性质证明了在局部域上有类似的结果ｈ_ｐ（Ｒ^ｎ）＝Ｆ_p.2⁰（Ｒ^ｎ），从而建立起函数空间之间的关系，并由此给出一个乘子定理．     

关于广义Calderon－Zygmund算子

本文讨论了θ（ｔ）型和（ｌｏｇ，θ）型Ｃａｌｄｅｒóｎ－Ｚｙｇｍｕｎｄ算子在加权Ｈａｒｄｙ型空间ＨＡ_w^p上的有界性，θ（ｔ）型Ｃａｌｄｅｒóｎ－Ｚｙｇｍｕｎｄ算子在Ｈａｒｄｙ型加权块空间上的有界性，以及广义的ｗ－Ｃａｌｄｅｒóｎ－Ｚｙｇｍｕｎｄ算子是Ｈ^Ap_w到ＨＡ^p上的有界算子．     

B值L′极值鞅变换的Lp收敛性

本文运用 Ｋｒｏｎｅｃｋｅｒ引理的推广形式对取值于 Ｂａｎａｃｈ空间 Ｂ上的 Ｂ值 Ｌ′极限鞅Ｘ＝（Ｘ_ｎ，Ｆ_ｎ）_ｎ≥0，关于实值可预报序列 Ｖ＝（Ｖ_ｎ，Ｆ_ｎ）_ｎ≥１的鞅变换Ｙ＝((?)V_k(X_k-X_k-1)Ｆ_ｎ）_ｎ≥１的Ｌ^p收敛性进行讨论，获得一     

关于常曲率空间中有限点集的几何不等式

本文用代数方法建立了ｎ维球面型空间Ｓ_ｎ（Ｋ）和ｎ维双曲空间Ｈ_ｎ（Ｋ）中有限点集的点与点两两之间之距离的一类几何不等式，本文还建立了ｎ维欧氏空间Ｅ^ｎ中共球有限点集的一类几何不等式．作为本文结果的应用，简洁地得出［３］中的一个重要结果，并得出Ｅ^ｎ中有限点集的两个几何不等式     

关于G-Matlis自反模的换环定理

设Ｒ和Ｔ是Ｎｏｅｔｈｅｒ完备半局部环，Ｒ→Ｔ是环同态．本文证明了，若Ｔ是有限生成或ＡｒｔｉｎＲ－模，Ｍ为Ｇ－Ｍａｔｌｉｓ自反Ｒ－模，则对所有ｎ≥０，Ｅｘｔ^Ｒ_ｎ（Ｔ，Ｍ），Ｅｘｔ^Ｒ_ｎ（Ｍ，Ｔ），Ｔｏｒ^Ｒ_ｎ（Ｔ，Ｍ）以及Ｔｏｒ^Ｒ_ｎ（Ｍ，Ｔ）均是Ｇ－Ｍａｔｌｉｓ自反Ｔ－模．所得结果推广了Ｒ．Ｂｅｌｓｈｏｆ的结果．     

半值环的两个交换结果

定理１设Ｒ是半值环，ｎ为固定的正整数，如果Ｒ满足条件：存在依赖于(?)_ｘ，ｙ的两个字ｋ（Ｘ，Ｙ），ｔ（Ｘ，Ｙ），其中｜ｋ｜_X＞１，｜ｔ｜_X＝１，｜ｋ｜_Y≥｜ｔ｜_Y，｜ｔ｜_Y≤ｎ，使ｋ（ｘ，ｙ）－ｔ（ｘ，ｙ）∈Ｉ（Ｒ），则Ｒ是交换环。定理２设Ｒ是半值环，如果Ｒ满足条件：存在正整数ｍ＝ｍ（ｘ，ｙ）＞１，ｎ＝ｎ（ｙ），使得（ｘ^ｎｙ）^m－ｘ     

一类子空间格

令Ｖ_n（ｑ）是具ｑ个元素的有限域上的ｎ维向量空间．Ｃ［ｎ,ｋ］是Ｖ_n（ｑ）中与某ｋ维子空间相交不为零空间之子空间全体按包含关系所成偏序集,Ｗ_m为其Ｗｈｉｔｎｅｙ数（０≤ｍ≤ｎ）．本文证明了Ｃ［ｎ,ｋ］具Ｓｐｅｒｎｅｒ性质和单峰性质．进一步地,W_m²-qW_m-1W_m+1作为ｑ的多项式具有非负系数,并且W₀≤W_n≤W₁≤W_n-1≤W₂≤…．     

Sobolev空间的实内插

本文求出了Sobolev空间L_k^∞,BMO_k与L_k^p,H_k^p(0 < p < ∞)之间的实内插空间.     

最佳有理L∝逼近的存在性

设Ｒ_ｆ（ｐ）∈Ｒ［ａ，ｂ］是函数ｆ的最佳有理Ｌ_p（１≤ｐ＜∞）逼近，Ｅ_ｆ（ｐ）＝‖ｆ－Ｒ_ｆ（ｐ）‖ｐ。本文证明了Ｅ_ｆ（ｐ）／（ｂ－ａ）^1/p是ｐ单调增加且有界的函数。当ｆ∈Ｌ_∞时，ｆ的最佳有理Ｌ_∞逼近必存在。     

乘积空间上Marcinkiewicz积分的Lp有界性

本文证明了乘积空间Rⁿ×R^m上Marcinkiewicz积分μ_Ω（f）的L^p有界性,其中Ω∈L（log⁺L）^2β（S^n-1×S^m-1）,β>1.     

On the embedding of BV space into Besov-Orlicz space

We give a sufficient (and, in the case of a compact domain, a necessary) condition for the embedding of Sobolev space of functions with integrable gradient into Besov-Orlicz spaces to be bounded. The condition has a form of a simple integral inequality involving Young and weight functions. We provide an example with Matuszewska-Orlicz indices of involved Orlicz norm equal to one. The main tool is the molecular decomposition of functions from a BV space.     

Planar and affine spaces

In this note, we characterize finite three-dimensional affine spaces as the only linear spaces endowed with set Ω of proper subspaces having the properties (1) every line contains a constant number of points, say n, with n>2; (2) every triple of noncollinear points is contained in a unique member of Ω; (3) disjoint or coincide is an equivalence relation in Ω with the additional property that every equivalence class covers all points. We also take a look at the case n=2 (in which case we have a complete graph endowed with a set Ω of proper complete subgraphs) and classify these objects: besides the affine 3-space of order 2, two small additional examples turn up. Furthermore, we generalize our result in the case of dimension greater than three to obtain a characterization of all finite affine spaces of dimension at least 3 with lines of size at least 3.     

Completeness of quasi-normed symmetric operator spaces

We show that (generalized) Calkin correspondence between quasi-normed symmetric sequence spaces and symmetrically quasi-normed ideals of compact operators on an infinite-dimensional Hilbert space preserves completeness. We also establish a semifinite version of this result.     

On the Incidence Geometry of Grassmann Spaces

In this paper we identify some properties on the point-line structure of Grassmannians which are useful tools to characterize the incidence geometry of Grassmann varieties and of their special quotients.     

Countable compact Hausdorff spaces need not be metrizable in ZF

We show that the existence of a countable, first countable, zero-dimensional, compact Hausdorff space which is not second countable, hence not metrizable, is consistent with ZF.

     

二次对偶空间的k-光滑性特性

深入研究了Banach空间X的二次对偶空间的k-光滑性,给出了Banach空间X的二次对偶空间为k-光滑的若干特征刻画.     

The classical Banach spaces

In this paper we study some structural and geometric properties of the quotient Banach spaces , where is an arbitrary set, is an Orlicz function, is the corresponding Orlicz space on and , being the ideal of elements with finite support. The results we obtain here extend and complete the ones obtained by Leonard and Whitfield (Rocky Mountain J. Math. 13 (1983), 531-539). We show that is not a dual space, that , if for every , that has no smooth points, that it cannot be renormed equivalently with a strictly convex or smooth norm, that is a Grothendieck space, etc.