STABILITY OF SEMI-FREDHOLM PROPERTIESIN COMPLEX INTERPOLATION SPACES

摘要

In this paper, we show that for interpolation morphisms S and the complex interpolation method the set of all B E (0,1) such that S_([θ]) is a semi-Fredholm operator is open and the nullities, deficiencies and the indices of S_([θ] are locally constant on this set.