A functional calculus for continuous affine operators

Abstract

In the Appendix to a recent paper by J.J. Koliha and A.P. Leung (Math. Ann.216 (1975), 273–284), a functional calculus for continuous affine operators was constructed on the basis of the Taylor-Dunford calculus. This calculus applied only to functions defined and analytic in an open set containing the spectrum of an operator and the point λ = 1. In the present paper I examine the affine resolvent, and develop independently a more general calculus applicable to functions which are analytic in any open neighbourhood of the spectrum of an affine operator.