Eigenfunction expansions and spectral projections for isotropic elasticity outside an obstacle

We consider the operator − −α grad div acting on an exterior domain Ω in Rn (withα >0 and n = 2, 3) subject to Dirichlet boundary conditions. The spectral resolution for the operator is written in terms of an expansion of generalized eigenfunctions.  2004 Elsevier Inc. All rights reserved.