Stability of semi-Fredholm properties in complex interpolation spaces

Förster, Karl-Heinz; Günther, Kerstin

doi:10.1090/S0002-9939-2011-10761-5

Stability of semi-Fredholm properties in complex interpolation spaces
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by Karl-Heinz Förster and Kerstin Günther PDF

Proc. Amer. Math. Soc. 139 (2011), 3561-3571 Request permission

Abstract:

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

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