Lr-variational Inequality for Vector Fields and the Helmholtz-Weyl Decomposition in Bounded Domains

We show that every L-r-vector field on Omega can be uniquely decomposed into two spaces with scalar and vector potentials, and the harmonic vector space via operators rot and div, where Omega is a bounded domain in R-3 with the smooth boundary partial derivative Omega. Our decomposition consists of two kinds of boundary conditions such as u . v|(partial derivative Omega) = 0 and u x v |(partial derivative Omega) = 0, where v denotes the unit outward normal to partial derivative Omega. Our results may be regarded as an extension of the well-known de Rham-Hodge-Kodaira decomposition of C-infinity-forms on compact Riemannian manifolds into L-r-vector fields on Omega. As an application, the generalized Blot-Savart law for the incompressible fluids in Omega is obtained. Furthermore, various bounds of u in L-r for higher derivatives are given by means of rot u and div u.