Decomposition of smooth functions of two multidimensional variables
2000 Mathematics Subject Classification: 49J52, 49J50, 58C20, 26B09.We show that the properties of dense subdifferentiability and of trustworthiness are equivalent for any subdifferential satisfying a small set of natural axioms. The proof relies on a remarkable property of the subdifferential of the inf-convolution of two (non necessarily convex) functions. We also show the equivalence of the dense subdifferentiability property with other basic properties of subdifferentials such as a weak* Lipschitz...
On donne une condition suffisante explicite et générique pour qu’une forme de Pfaff à deux variables complexes ait ses feuilles denses tant localement que globalement.
Given a compact manifold and real numbers and , we prove that the class of smooth maps on the cube with values into is strongly dense in the fractional Sobolev space when is simply connected. For integer, we prove weak sequential density of when is simply connected. The proofs are based on the existence of a retraction of onto except for a small subset of and on a pointwise estimate of fractional derivatives of composition of maps in .
In this paper we introduce a new class of differential graded algebras named DG -algebras and present Lie operations on this kind of algebras. We give two examples: the algebra of forms and the algebra of noncommutative differential forms of a -algebra. Then we introduce linear connections on a -bimodule over a -algebra and extend these connections to the space of forms from to . We apply these notions to the quantum hyperplane.
In this article we formalized the Fréchet differentiation. It is defined as a generalization of the differentiation of a real-valued function of a single real variable to more general functions whose domain and range are subsets of normed spaces [14].