F. Menéndez-Conde. Eigenfunction expansions and spectral projections for isotropic elasticity outside an obstacle, Journal of Mathematical Analysis and Applications 299 (2004) 676689. Preprinted
We consider the operator ??? grad div acting on an exterior domain ? in Rn (with? >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.