A bounded linear operator T on a complex Banach space X is called an operator of Saphar type if its kernel is contained in its generalized range $⋂_{n=1}^{∞} T^n(X)$ and T is relatively regular. For T of Saphar type we determine the supremum of all positive numbers δ such that T - λI is of Saphar type for |λ| < δ.
Mathematisches Institut I, Universität Karlsruhe, Postfach 6980, D-76128 Karlsruhe, Germany
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