Normal solvability of linear elliptic problems

The paper is devoted to general linear elliptic problems in Holder spaces. We consider unbounded domains and define limiting problems at infinity. We give a necessary and sufficient condition of normal solvability through uniqueness of solutions of limiting problems. We study a structure of spaces dual to Holder spaces and specify the subspace of functionals. which provide the condition of normal solvability. This allows us to prove that for Fredholm operators all limiting operators are invertible.