一类由Hamilton对生成的Hamilton算子

设θ１与θ２组成一个Ｈａｍｉｌｔｏｎ对，且设θ２可逆。记Φ＝θ１θ１－１。本文证明了：Φｉθ２是一类Ｈａｍｉｌｔｏｎ算子，其中ｃｉ（ｉ＝０，１，２，３）是任意常数。     

关于P（△）的强端点的性质

本文首先引进了单位园△上算子值解析函数族：Ｐ（△）＝｛ｆ（Ｚ），ｆ（Ｚ）＝Ｉ＋Ｂ（Ｉ）Ｚ＋Ｂ（２）Ｚ￣２＋…在△内解析，且Ｒｅｆ（Ｚ）＞０，Ｂ（ｎ）为Ｈｉｌｂｅｒｔ空间Ｈ上的正规算子，ｎ＝１，２…｝的强端点的概念，然后指出Ｐ（△）中形如Ｉ＋Ｂ（ｎ）Ｚ￣ｎ＋Ｂ（ｎ＋１）Ｚ￣（ｎ＋１）＋…的元素成Ｘ＿１Ｐ（△）的一个强端点的必要条件为Ｂ（ｎ）不是自伴可逆算子。     

FIXED POINTS AND COUPLED FIXED POINTS FOR INCREASING OPERATORS WITH APPLICMIONS TO DIFFERENTIAL INCLUSIONS IN BANACH SPACES

ＦＩＸＥＤＰＯＩＮＴＳＡＮＤＣＯＵＰＬＥＤＦＩＸＥＤＰＯＩＮＴＳＦＯＲＩＮＣＲＥＡＳＩＮＧＯＰＥＲＡＴＯＲＳＷＩＴＨＡＰＰＬＩＣＭＩＯＮＳＴＯＤＩＦＦＥＲＥＮＴＩＡＬＩＮＣＬＵＳＩＯＮＳＩＮＢＡＮＡＣＨＳＰＡＣＥＳＺＨＡＮＧＳＨＩＳＨＥＮＧＡＮＤＨＵ...     

On distributionally regenerative processes

The paper is concerned with characterization results for distributional regeneration. It is shown that distributional regeneration is equivalent to renewal representation of the associated (shift) Markov operator. A sufficient condition for the distributional regeneration of the transfer operator in terms of variation is also formulated. Finally, a minorization condition is formulated and proved to be sufficient for recurrent co-Feller operators.     

一类非连续算子不动点存在的充分必要条件

文章证明了不加连续条件的一类凹算子存在不动点的充分必要条件     

A trace class operator inequality

In this note, we generalize the inequality about the trace of positive semidefinite matrix trk(AB)?k(trA)k(trB) to Hilbert space, and obtain a relevant inequality about positive trace class operator.     

Entire radial solutions of elliptic systems and inequalities of the mean curvature type

In this paper we study first nonexistence of radial entire solutions of elliptic systems of the mean curvature type with a singular or degenerate diffusion depending on the solution u. In particular we extend a previous result given in [R. Filippucci, Nonexistence of radial entire solutions of elliptic systems, J. Differential Equations 188 (2003) 353-389]. Moreover, in the scalar case we obtain nonexistence of all entire solutions, radial or not, of differential inequalities involving again operators of the mean curvature type and a diffusion term. We prove that in the scalar case, nonexistence of entire solutions is due to the explosion of the derivative of every nonglobal radial solution in the right extremum of the maximal interval of existence, while in that point the solution is bounded. This behavior is qualitatively different with respect to what happens for the m-Laplacian operator, studied in [R. Filippucci, Nonexistence of radial entire solutions of elliptic systems, J. Differential Equations 188 (2003) 353-389], where nonexistence of entire solutions is due, even in the vectorial case, to the explosion in norm of the solution at a finite point. Our nonexistence theorems for inequalities extend previous results given by Naito and Usami in [Y. Naito, H. Usami, Entire solutions of the inequality div(A(|Du|)Du)?f(u), Math. Z. 225 (1997) 167-175] and Ghergu and Radulescu in [M. Ghergu, V. Radulescu, Existence and nonexistence of entire solutions to the logistic differential equation, Abstr. Appl. Anal. 17 (2003) 995-1003].     

多线性Calderón-Zygmund算子的加权有界性

建立了多线性Calderón-Zygmund算子在比幂权空间更一般的Herz空间和Herz型Hardy空间上的有界性.作为推论,得到了该算子的幂权估计.在这些幂权估计中,权指标可以突破Ap权的指标限制,显示出和经典Calderón-Zygmund算子本质的区别.     

一类由Hadamard乘积定义的函数子类

设p为正整数,)(pA表示单位圆盘内形如+=+=1)(pkkkpzazzf的解析函数全体,对给定的复 常数p-l及)(zf )(pA, 用 )()()(zfzhzfJ*=ll 定义算子lJ,其中kpkzkpzhlll++==)(,文章得出当)()()(alpnRzfJ(p相似文献   

Positive Schatten(-Herz) Class Toeplitz Operators on the Half-space

On the harmonic Bergman space of the half-space, we give characterizations for an arbitrary positive Toeplitz operator to be a Schatten (or Schatten-Herz) class operator in terms of averaging functions and Berezin transforms. Examples are provided to show that various results are sharp. This research was supported by KOSEF(R01-2003-000-10243-0).