Caratheodory operator of differential forms

Tang Zhaoyang, Zhu, Zhu Jianmin

Description

This article is devoted to extensions of some existing results about the Caratheodory operator from the function sense to the differential form situation. Similarly as the function sense, we obtain the convergence of sequences of differential forms defined by the Caratheodory operator. The main result in this article is the continuity and mapping property from one space of differential forms to another under some dominated conditions.

Sujets

• Differential form

Informations

• Publié par: biomed
• Publié le: 01 janvier 2011
• Nombre de lectures: 3
• Langue: English

Extrait

Tang and Zhu Journal of Inequalities and Applications 2011, 2011 :88 http://www.journalofinequalitiesandapplications.com/content/2011/1/88

R E S E A R C H Open Access Caratheodory operator of differential forms Zhaoyang Tang * and Jianmin Zhu

* Correspondence: tzymath@gmail. Abstract com Department of Mathematics and This article is devoted to extensions of some existing results about the Caratheodor System Science, National University y of Defense Technology, Changsha, operator from the function sense to the differential form situation. Similarly as the PR China function sense, we obtain the convergence of sequences of differential forms defined by the Caratheodory operator. The main result in this article is the continuity and mapping property from one space of differential forms to another under some dominated conditions. Keywords: differential forms, Caratheodory operator, continuity of operator

1 Introduction It is well known that differential forms are generalizations of differentiable functions in R N and have been applied to many fields, such as potential theory, partial differential equations, quasi-conformal mappings, nonl inear analysis, electromagnetism, and con- trol theory [1-12]. One of the important work in the field of d ifferential forms is to develop various kinds of estimates and inequalities for differential forms under some conditions. These results have wide applications in the A-har monic equation, which implies more ver- sions of harmonic equations for functions [1,5,6]. The Caratheodory operator arose from th e extension of Peano theorem about the existence of solutions to a first-order ordinary differential equation, which says that this kind equation has a solution under relatively mild conditions. It is very interesting to characterize equivalently the Caratheodory ’ s conditions and the continuity of Car- atheodory operator, which form classic examples to discuss boundedness and continu- ity of nonlinear operators and play an important part in advanced functional analysis. For general function space, we define the Caratheodory operator as in [13,14]. Definition 1.1 . Suppose that G is measurable in R N , and 0 < mesG ≤ + ∞ . We say that function f ( x, ω )( x Î G , -∞ < ω < + ∞ ) satisfies the Caratheodory conditions, if 1. for almost all x Î G, f ( x, ω ) is continuous with respect to ω ; and 2. for any ω , f ( x, ω ) is measurable about x on G. For the function f ( x, ω ) with Caratheodory condition s, we define the Caratheodory operator T : G × R ® R by T ω ( x ) = ( x , ω ( x )) There are some essential results for Caratheodory operator as follows.

© 2011 Tang and Zhu; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.