首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 58 毫秒
1.
非退化扩散过程的极性的必要性   总被引:3,自引:1,他引:2  
设X(t)是一N维非退化扩散过程.设 E(0,∞)和 F RN都为紧集.本文给出了:P(X-1(F)∩E≠φ)>0,P(X-1(F)≠φ)>0和P(X(E)≠φ)>0的充分条件.证明了:i)设 N≥ 3,a)若 dim(F)<N-2,则 P(X-1(F)=φ)=1; b)若dim(F)>N-2,则 P(X-1(F)≠φ)>0; c)存在 F1 RN,F2 RN,dim(F1)=dim(F2)=N-2,但有P(X-1(F1)=φ)=1,P(X-1(F2)≠φ)>0.ii)设N=1,a)若dim(E)>1/2,则x∈R1,P(X-1(x)∩E≠φ)>0;b)存在E(0,∞),dim(E)=1/2,使得x∈R1,P(X-1(x)∩E≠φ)>0.以上这些结果,不仅仅是Brown运动的推广,即使就Brown运动的情形而言,其中有些结果也是新的.  相似文献   

2.
郑学良 《数学季刊》1998,13(4):29-32
§1. IntroductionandNarratationoftheTheoremIffunctionfisanalyticindomainDandf′(z)≠0atpointz,wedefinetheschwarzianderivativeoffasSf(z)=(f″(z)f′(z))′-12(f″(z)f′(z))2.(1.1)  Foralocallyunivalentholomorphicfunction,itsSchwarzianderivativeisclear.Atpoles,t…  相似文献   

3.
本文证明文[2]中的猜测不成立设f为区间[0,1]上实值函数,满足条件(a)f在[0,1]上有界,(b)f在[0,1]上连续,(c)f(x)不存在,试问是否存在?1982年S.Ricci[1]给出F′+(0)存在的例子:最近J.klippert[2]给出F′+(0)不存在的例子:J.klippert提出如下猜测:如果f满足(a)-(c)并且f的相邻零点之间距离依,α>1,趋近于零,则F′+(0)=0,我们证明上述猜测不真,此外,我们给出F′+(0),存在的一个充分条件。  相似文献   

4.
设F={f1,…,fM}是一个次数大于1的多项式集合。我们证明了在一定条件下Fatou集F(F)没有游荡区域。更确切地说,对于F(F)的每一个分支Ω,存在整数m≥0,n≥0,m≠n和λ∈∑M使得Wmα(Ω)和Wnα(Ω)落入F(F)的同一分支  相似文献   

5.
关于迭代函数方程f~2(x)=af(x) bx的通解   总被引:2,自引:0,他引:2  
设λ的二次三项式λ2-aλ-b的两个零点为λ1=r,λ2=s(a及b为实数).对0<r<s,r<0<s≠-r及r=s≠0这三种情形,J.Matkowski与WeinianZhang在“Methodofcharacteristicsforfunctionalequationsinpolynomialform”一文中给出了迭代函数方程f2(x)=af(x)+bx,对任x∈R;f∈C0(R,R)(1)的通解,并证明了当r及s非实数时方程(1)无解.对r=-s≠0的情形,M.Kuczma已给出了方程(1)的通解.本文则对r<s<0及rs=0这两种情形给出了方程(1)的通解.此外,本文还给出了r<0<s≠-r时关于方程(1)的通解的一个简洁的证明  相似文献   

6.
本文证明了:设R为charR≠0,G为有限生成的Abel群,则:P∈F=(RG)当且仅当s>0,使得P∈F=(RG).  相似文献   

7.
设ξ={f1,…,fM}是一个镒数大于1的多项式集合。我们证明了在一定条件下Fatou集F没有游荡区域。更确切地说,对于F的每一个分支Ω,存在整数m≥0,n≥0,m≠n和λ∈ΣM使得W^mα(Ω)和W^nα(Ω)落入F同一分支。  相似文献   

8.
1引言 考虑如下的具有二角结构的作线性系统LPTS(linearly parameterized triangularstructure).其中x=(x1,.……xn)T0∈Rn为系统的状态,u∈R为控制输入,θ∈Rp为未知常值参数向量,γi0及γi′,β′(x)β0为已知的光滑非线性函数,γi0(0)=0,γi′(0)=0,β0(0)≠0;(i=1,…,n),对这样的系统,D.Seto,A.M.Annaswamy和J.Baillieul在[1]中进行了讨论,但是他们对同一参数用了多个估计,使得系…  相似文献   

9.
利用对称变换求二次曲线的切线   总被引:1,自引:0,他引:1  
程涛 《数学通报》1994,(6):40-41
利用对称变换求二次曲线的切线程涛(乌鲁木齐铁路局教育学院830011)设C是一条非退化的二次曲线,其方程为F(x,y)=0;M(h,k)是C上一点.对C上的点P(x,y),作以M为中心的对称变换T:MP′=PM,T下的象就是C′:F(2h—x,2k-...  相似文献   

10.
椭圆一个定理的又一初等证明   总被引:1,自引:0,他引:1  
定理 椭圆C:x2a2+y2b2=1(a>b>0)有且仅有两条对称轴:直线x=0和y=0.文[1]指出,这个定理的证明一般要用到仿射几何知识,同时文[1]给出了一个初等证明.笔者再给出这个定理的又一种初等证明如下.定理的证明 易验证直线x=0和y=0均是椭圆C的对称轴.因点B(0,b)关于直线x=k(k≠0)的对称点B′(2k,b)不在椭圆C图1上,故直线x=k(k≠0)不是椭圆C的对称轴.设F1,F2是椭圆C的两个焦点,椭圆C的长轴A1A2关于直线l:y=kx+n(k,n至少有一个不等于零)的…  相似文献   

11.
王漱石 《数学研究》2000,33(2):128-134
设Γ为非空集,X为实Banach空间,本研究赋Day范数的c0(Γ,X)的光滑点,强光滑点,暴露点和强暴露点。  相似文献   

12.
Intuitively, non-smooth points might look like exposed points. However, in this paper we show that real Banach spaces having dimension greater than or equal to three can be equivalently renormed to obtain non-smooth points which are also non-exposed.  相似文献   

13.
We find the extreme points and the smooth points of the unit ball of the Banach space n of all real symmetric (n×n)-matrices.  相似文献   

14.
Byσthe author denotes the areal measure on the unit disk D=z: |z|<1. Let H'p={f(z): f(z) is analytic in D and 1/π∫D|f(z)|p dσ<+∞}. Let B(H'p)={f:f∈H'p and 1/π∫D|f(z)|p dσ1. This article researches the support points and extreme points of B(H'p).  相似文献   

15.
Let G be a graph and f:GG be a continuous map. Denote by P(f), R(f) and Ω(f) the sets of periodic points, recurrent points and non-wandering points of f, respectively. In this paper we show that: (1) If L=(x,y) is an open arc contained in an edge of G such that {fm(x),fk(y)}⊂(x,y) for some m,kN, then R(f)∩(x,y)≠∅; (2) Any isolated point of P(f) is also an isolated point of Ω(f); (3) If xΩ(f)−Ω(fn) for some nN, then x is an eventually periodic point. These generalize the corresponding results in W. Huang and X. Ye (2001) [9] and J. Xiong (1983, 1986) [17] and [19] on interval maps or tree maps.  相似文献   

16.
A short note about exposed points in real banach spaces   总被引:1,自引:0,他引:1  
We express the set of exposed points in terms of rotund points and non-smooth points.As long as we have Banach spaces each time"bigger",we consider sets of non-smooth points each time"smaller".  相似文献   

17.
In this paper the following results are got 1. We prove that the order definitionwhich is given by J.F. Trawb on the iterative function is wrong. 2. A existent theorem on the repulsive point is given. 3. We give some theorems to judge a fixed point of iterative function. They all imporve the Ostrowski's theorems.  相似文献   

18.
设T={f(z):f(z)在单位圆盘|z|<1上解析,f(z)=z ,an是实数, |an|≥|an 1|且|an|≤1}.该文找出了解析函数族T的极值点与支撑点.  相似文献   

19.
Given a generic immersionf:S 1S 2 of a circle into the sphere, we find the best possible lower estimation for the number of triple points of a generic immersionF: (M, S 1)→(B 3,S 2) extendingf, whereM is an oriented surface with boundary ∂M=S 1,B 3 is the 3-dimensional ball with boundaryS 2. Supported by the Hungarian National Science and Research Foundation OTKA 2505 Supported by the Hungarian National Science and Research Foundation OTKA T4232 This article was processed by the author using the Springer-Verlag TEX P Jour1g macro package 1991.  相似文献   

20.
This paper presents a property of geometric and topological nature of Gateaux differentiability points and Fréchet differentiability points of almost CL-spaces. More precisely, if we denote by a maximal convex set of the unit sphere of a CL-space , and by the cone generated by , then all Gateaux differentiability points of are just n-s, and all Fréchet differentiability points of are (where n-s denotes the non-support points set of ).

  相似文献   


设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号