VARIOUS NOTIONS OF ORTHOGONALITY IN NORMED SPACES

In this paper, we present various notions and aspects of orthogonality in normed spaces. Characterizations and generalizations of orthogonality are also consid-ered. Results on orthogonality of the ran...     

HYERS—ULAM—RASSIAS STABILITY OF QUADRATIC FUNCTIONAL EQUATIONS IN BANACH MODULES OVER A C^＊—ALGEBRA

The authors prove the Hyers-Ulam-Rassias stability of the quadratic mapping in Banach modules over a unital C*-algebra, and prove the Hyers-Ulam-Rassias stability of the quadratic mapping in Banach modules over a unital Banach algebra.     

ON L^P-MATRICIALLY NORMED SPACES

1Introduction and PreliminariesThroughout this paper,we consider linear spaces over the complex numbers C.Given alinear space X and integers m and n,let Mm,n(X)=X?Mm,n denote the linear space ofm×n matricesx=?????x.x..m1,1,1.x..xm1,n,n?????with entries x…     

HYERS-ULAM-RASSIAS STABILITY OF SECOND ORDER PARTIAL DIFFERENTIAL EQUATIONS

In this paper, using Banach’s contraction principle, we consider the Hyers-UlamRassias stability of nonlinear partial diferential equations. An example is given to demonstrate the applicability of our results.     

ASYMPTOTIC BEHAVIOR OF OPERATORS OF PROBABILISTIC TYPE IN L_p SPACES

ＡＳＹＭＰＴＯＴＩＣＢＥＨＡＶＩＯＲＯＦＯＰＥＲＡＴＯＲＳＯＦＰＲＯＢＡＢＩＬＩＳＴＩＣＴＹＰＥＩＮＬ_ｐＳＰＡＣＥＳ￥ＣＨＥＮＷＥＮＺＨＯＮＧ；ＣＵＩＺＨＥＮＬＵ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓＸｉａｍｅｎＵｎｉｖｅｒｓｉｔｙ，Ｘｉ?..     

STABILITY OF DELAY DIFFERENCE EQUATIONS IN BANACH SPACES

1 IntroductionDiscrete reaction--diffusion type partial difference equations llave recentlybeen introduced by a number of authors as modeIs for the study of spatiotem-poral chaos (see e.g. [2,3j). Stability criteria have also been derived fOr suchequatioIls which invoIve two time-level processes (see e.g. [1l) as well as three-level processes (see e.g. [9]). In this paper, we will study no11linear three--levc1partia1 diffcrence equations in an abstract setting and derive stability criteriafo…     

Banach空间泛函微分方程的正解

本文利用锥理论研究Ｂａｎａｃｈ空间泛函微分方程正解的存在性,在紧型条件下获得一个新结果。     

非阿基米德 Menger 概率度量空间中单值和集值映象的不动点定理

J.Achari 在[1]中证明了非阿基米德Menger空间中几个不动点定理,近年来不少人讨论过这类问题.在此基础上,本文给出非阿基米德 Menger 概率度量空间中单值和集值映象的几个不动点定理,本文的结果改进和发展了引文[1,3]中相应的结果.文中所用到的有关概率度量空间的概念和符号均见[4].定义1.设 E 是一非空集,为一切左连续的分布函数的全体.称(E,(?))为非     

Banach空间中非线性积分微分方程的迭代解法

通过构造单调迭代序列，研究了Ｂａｎａｃｈ空间中非线性积分微分方程在Ｓｔｕｒｍ边值条件下的最大解与最小解的存在性及其迭代求法。     

UNIFORM ASYMPTOTIC STABILITY OF FUNCTIONAL DIFFERENTIAL EQUATIONS

With the help of a Liapunov functional with seml-negative definite derivative,Barbashin-Krasovskii's theorem is extended to nonautonomous functional differentialequations,a reducing dimension approach is presented for the uniform asymptotic stabilityof high dimension systems,and some sufficient conditions of uniform asymptotic stabilityare obtained.     

泛函微分方程的Lipschitz指数稳定性

提出泛函微分方程的Lipschitz指数稳定性概念,给出了利用Liapunov泛函数研究Lipschitz指数稳定性的条件。     

广义泛函微分方程解的稳定性

本文首先给出广义泛函微分方程解的稳定性的概念,同时建立了有关稳定与不稳定的二个判据,然后作为例子,讨论二阶线性常系数广义微分差分程,得到了这类系统有关稳定与不稳定的若干结果,并发现了一些关于稳定性的分支或类似于分支的现象。     

赋范线性空间中同时远达点的唯一性

1 引言 设X为一实赋范线性空间,给定X中的子集G和有界子集K,令(?)和C分别表示X的所有非空有界子集与相对紧子集的全体,对A∈B,记 若x_(0)∈K满足sup||a-x_(0)||=Fk(A),则称x_(0)是A关于K的同时远达点,A关于K的同时远达点的全体记为Q_(K)(A),即     

WELL-POSEDNESS IN CRITICAL SPACES FOR THE FULL COMPRESSIBLE MHD EQUATIONS

In this paper we prove local well-posedness in critical Besov spaces for the full compressible MHD equations in R^N, N≥ 2, under the assumptions that the initialdensity is bounded away from zero. The proof relies on uniform estimates for a mixed hyperbolic/parabolic linear system with a convection term.     

CHARACTERISATIONS OF OPERATORS OF LOWER SEMI-FREDHOLM TYPE IN NORMED LINEAR SPACES

Abstract

Let X and Y be normed linear spaces. A linear operator T: D(T) ? X → Y is called an F-operator if its adjoint T′: D(T) ? Y′ → D(T)' is a φ+ -operator, i.e. has closed range and finite dimensional-kernel. Characterisations of an F_-operator T are obtained in the general case and in the case when T is closable. Unbounded strictly cosingular operators are defined and shown to belong to the class of F_ -admissible pertubations whenever Y is complete.     

THE HAHN-BANACH EXTENSION PROPERTY IN A CLASS OF NORMED SPACES

Abstract

Answering to a question formulated by A.F. MONNA, we study the Hahn-Banach extension property and other related topics within the context of A-normed spaces over valued fields.     

赋范线性空间中的广义凸集

文[1]拓广凸集的概念,在 R~(?) 中引入了伪凸、拟凸等广义凸集的概念,获得了它们的一些性质,因而可使得优化理论的研究更为深入.熟知,逼近理论在优化中的应用是非常广泛的(见[2]),本文试图把广义凸集引入赋范线性空间中,并侧重探究其逼近性质.自然,文[1]在 R~(?) 中得到的广义凸集的一些性质,大多数在赋范空间中都是成立的,且证明     

Banach空间一阶微分方程终值问题的解

本文利用新的比较结果和半序理论研究Ｂａｎａｃｈ空间中一阶非线性微分方程终值问题的最小解和最大解的存在性,改进和推广了某些已知结果．