On correctors for linear elliptic homogenization in the presence of local defects

Abstract

We consider the corrector equation associated, in homogenization theory, to a linear second-order elliptic equation in divergence form , when the diffusion coefficient is a locally perturbed periodic coefficient. The question under study is the existence (and uniqueness) of the corrector, strictly sublinear at infinity, with gradient in Lr if the local perturbation is itself Lr, . This work follows up on previous works of ours, providing an alternative, more general and versatile approach, based on an a priori estimate, for this well-posedness result. Equations in non-divergence form such as are also considered, along with various extensions. The case of general advection–diffusion equations is postponed to a future work. An appendix contains a corrigendum to one of our earlier publication.