Abstract. We determine when the average of two isometries on a Banach space of analytic vector valued functions is a projection. We also characterize the generalized bi-circular projections on a Banach space of absolutely continuous vector valued functions.
AMS Subject Classification
convex combination of isometries
Received May 21, 2013, and in revised form February 14, 2014. (Registered under 31/2013.)