On a mixed problem for the parabolic Lamé type operator

Abstract

We consider a boundary value problem for a Lam e type operator, which corresponds to a linearisation of the Navier-Stokes' equations for compressible

ow of Newtonian uids in the case where pressure is known. It consists of recovering a vector function, satisfying the parabolic Lam e type system in a cylindrical domain, via its values and the values of the boundary stress tensor on a given part of the lateral surface of the cylinder. We prove that the problem is ill-posed in the natural spaces of smooth functions and in the corresponding H older spaces; besides, additional initial data do not turn the problem to a well-posed one. Using the integral representation's method we obtain a uniqueness theorem and solvability conditions for the problem. We also describe conditions, providing dense solvabilty of the problem.