Extending Polynomials in Maximal and Minimal Ideals
Extending Polynomials in Maximal and Minimal Ideals
Given a homogeneous polynomial on a Banach space E belonging to some maximal or minimal polynomial ideal, we consider its iterated extension to an ultrapower of E and prove that this extension remains in the ideal and has the same ideal norm. As a consequence, we show that the Aron–Berner …