Resumen de Moving Weyl's Theorem from ⨍(T) to T

M. Febronio Rodríguez, B. P. Duggal, S.V. Djordjevic

• Schmoeger has shown that if Weyl’s theorem holds for an isoloid Banach space operator T ∈ B(X) with stable index, then it holds for f(T) whenever f ∈ Holo σ(T) is a function holomorphic on some neighbourhood of the spectrum of T. In this note we establish a converse