概率度量空间中一个新的不动点定理

概率度量空间中压缩型映象不动点定理的研究开始于1972年Schgal-Bharucha-Reid的工作[3]。以后不少人对概率度量空间中映象的不动点定理进一步讨论,特别是Istratescu的工作[4]把[3]中的结果作了重要的推广。最近张石生[2]对[3]、[4]中的结果作了进一步的推广,[2]中的结果包含了[3]、[4]的主要结果。 在此基础上,本文给出概率度量空间中压缩型映象的一个新的不动点定理。文中涉及的概念及引用的基本定理均见[1]。     

一类Krasnoselskii型不动点定理

本文给出两个新的不动点定理,其推广了著名的Krasnoselskii型的不动点定理及[6,7,9—11]中的某些近代的结果。     

一个集值映射的不动点定理

M.Lassonde在[3]中用逼近论和同伦方法证明了几个非凸集上的集值映射的不动点定理。本文推广了[3]中的定理3.15,得到一个较好的不动点定理及若干有用的推论。     

单调减凝聚映象的不动点定理

郭大钧[1]和[4]给出了单调减全连续映象的不动点定理,并用于核物理中一个非线性积分方程的求解。本文把它拓广到凝聚映象,从而拓广了[1]和[4]的结果。 定理 设E是Banach空间,P是E中一个正规锥,A:P→P是单调减凝聚映象。那末(i)A在P中至少有一个不动点x~*,θ≤x~*≤Aθ;(ⅱ)A~2在P中的不动点唯一时,A在P中的不动点唯一并且对任何x_0∈P作迭代序列     

抽象空间内的随机公共不动点定理

引言 随机算子的不动点理论是随机泛函分析的重要组成部分,它是研究随机算子方程解的存在唯一性的必要工具.因此有不少作者致力于将决定性不动点理论中的某些已知结果移植到随机分析中去。 最近张石生;陈绍仲;刘作述和丁协平都分别将距离空间和G-值距离空间中某些决定性不动点定理移植到随机算子的情形,推广了[1-3]和其他人的某些结果。 本文目的是首先在G-值距离空间内建立映象和映象对的某些公共不动点定理,这些定理的特例在适当附加假设下解答了Sastry:Naidv和Rhoades提出的尚待解决的问题,(见[7,p.25]和[8]的定义149,174,199),其次将所得到的某些结果随机化,建立了几个新的随机不动点定理,它们改进和推广了[1-6]中的某些重要结果。     

局部凸拓扑向量空间中的不动点定理

本文在局部凸拓扑向量空间中得到了几十新的不动点定理，推广了[2]中的几个重要结果。     

一个新的不动点定理

<正> 本文在作者工作[1]的基础上,利用Leray-Schauder度理论给出无穷维Banach空间中非线性全连续算子的一个新的不动点定理,此不动点定理把著名的锥拉伸和锥压缩不动点定理中的序关系换成了范数关系,从而具有特点.我们还举例说明了此不动点定理对于Hammerstein积分方程非零解存在性的应用.     

广义Kannan型压缩条件的注记

本文给出了 [4 ]中的广义Kannan型压缩条件下映象的一个不动点定理 ,说明了 [2 5]中广义Kannan型压缩条件下映象与 [1 ]中Kannan型压缩条件下映象具有一致的不动点存在性 .     

一般随机不动点定理及其应用

在本文中我们得到了一个一般的随机不动点定理,推广了Engl[4,7]和Bocsan[8]的主要结果.这一定理的有用性在于目前由许多作者用特殊方法得到的随机不动点定理[1,4,5-13]均能利用我们的一般定理(定理1和系1,2)得到,最后给出了我们的定理对随机积分和微分方程的应用.     

一类新的KKM定理及其应用*

本文得到一类新的KKM定理,统一和改进了[2,3,0,7,11]中的结果。作为应用,我们得到了几个匹配定理、重合定理、不动点定理、极大极小不等式定理及截口定理。     

关于“四元数自共轭矩阵与行列式的几个定理”的注记

本刊1985年第4期发表郝稚传的“四元数自共轭矩与行列式的几个定理”(称为〔1〕)的文章的主要工作分为两部分。〔1〕在英文摘要中写到:“(i)This essay has improvedthe conclusion of theorem 8 and theorem 9 in 〔2〕”即〔1〕之第一部分工作在于改进了〔2〕的定理8、9的结果,其根据就是〔1〕的定理1、2.〔1〕称定理1—若     

On the Equivalence of Minimax Theorems

In this note we show that Ky Fan's minimax theorem and its several generalizations such as König's minimax theorem [6], M. Neumann's minimax theorem [8] and Fuchssteiner-König's minimax theorem [3] are equivalent. We also give a direct proof for Fuchssteiner-König's minimax theorem on the basis of Eidelheit's well-known seperation theorem.     

An edge-coloration theorem for bipartite graphs with applications

An edge-coloration theorem for bipartite graphs, announced in [4], is proved from which some well-known theorems due to König [5] and the author [2, 3] are deduced. The theorem is further applied to prove the “dual” of a theorem due to Lovász [6].     

关于解析算子值函数的几个结果

关于复值解析函数Riesz—Dunford积分的Ky Fan定理由[1]推广到算子值解析函数,由此函数论中的很多定理得到了推广.本文的目的在于改进[1]中的结果,得到了较弱条件下的Pick定理,从而推广了[2]中的Julia引理,并简化了其证明过程.     

Anmerkungen zu einem lemma von hoàng tuy

In [1], [2] HOÀNG TUY gave an approach to the main theorems of the convex analysis and the convex optimization being based on a lemma; he has proved it by means o induction. In [1] the equivalence of the main theorems of convex optimization given in [1], [2] does not use a separation theorem or equivalent statements. In this note the author has proved that the lemma of HOÀNG TUY can be characterized as a special separation theorem and be obtained from a separation theorem of Eidelheit. That means that the lemma is equivalent to the theorem of Hahn-Banach.     

Existence of solution of the logarithmic diffusion equation with bounded above Gauss curvature

We give a simple proof of an extension of the existence results of Ricci flow of Giesen and Topping (2010, 2011) [15], [20], on incomplete surfaces with bounded above Gauss curvature without using the difficult Shi’s existence theorem of Ricci flow on complete non-compact surfaces and the pseudolocality theorem of Perelman [7] on Ricci flow. We will also give a simple proof of a special case of the existence theorem of Topping (2010) [16] without using the existence theorem of Shi (1989) [9].     

Zariski density in lie groups

In [7] Furstenberg gave a proof of Borel’s density theorem [1], which depended not on complete reducibility but rather on properties of the action of a minimally almost periodic group on projective space. In [9] and [10] the basic idea of this proof was extended in various ways to deal with other particular classes of Lie groupsG and closed subgroupsH of cofinite volume. In [5] Dani gives a more general form of the density theorem in whichH need only be non-wandering. In the present paper we define the condition ofk-minimal quasiboundedness, and prove that this condition is necessary and sufficient for the density theorem to hold ((2.4) and (2.6)). Here we replace the arguments of [9] and [10] simply by proofs that the groups considered there satisfy this condition (2.10). We extend the results of [9] and [10] by considering groups which are analytic rather than algebraic, and in the solvable case we completely characterize thek-minimally quasibounded groups (2.9). In the last section we give two applications of the density theorem.     

关于布尔关系友阵（英）

ＯｎＣｏｍｐａｎｉｏｎＢｏｏｌｅａｎＲｅｌａｔｉｏｎＭａｔｒｉｃｅｓＣｈａｏＣｈｏｎｇｙｕｎ（Ｄｅｐｔ．ｏｆＭａｔｈＵｎｉｖｏｆＰｉｔｔｓｂｕｒｇｈＰｉｔｔｓｂｕｒｇｈ，ＰＡ１５２６０）ＷａｎｇＴｉａｎｍｉｎｇ（Ｉｎｓｔ．ｏｆＭａｔｈ．Ｓｃｉｅｎｃｅ...     

A Fixed Point Theorem for Multi—valued Composite Increasing Operators

Ａ　Ｆｉｘｅｄ　Ｐｏｉｎｔ　Ｔｈｅｏｒｅｍ　ｆｏｒ　Ｍｕｌｔｉ－ｖａｌｕｅｄ　Ｃｏｍｐｏｓｉｔｅ　Ｉｎｃｒｅａｓｉｎｇ　ＯｐｅｒａｔｏｒｓＬｉＦｅｎｇｙｏｕ（李凤友）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，Ｔｉａｎｊｉｎ＇ＮｏｒｍａｌＵｎｉ...     

Growth properties of the q-Dunkl transform in the space $$L^{p}_{q,\alpha }({\mathbb {R}}_{q},|x|^{2\alpha +1}d_{q}x)$$ L q , α p ( R q , | x | 2 α + 1 d q x )

The Ramanujan Journal - Our aim in this work is to prove an analogue of Titchmarsh’s theorem [19, Theorem 84] and Younis’s theorem [20, Theorem 3.3] on the image under the q-Dunkl...