Departamento de Matemáticas, Universidad de Cádiz, Puerto Real, Cádiz, 11510, Spain ; Department of Mathematical Sciences, Kent State University, Kent, Ohio 44242
Abstract:
The aim of this paper is to study the set of all -summand vectors of a real Banach space . We provide a characterization of -summand vectors in smooth real Banach spaces and a general decomposition theorem which shows that every real Banach space can be decomposed as an -sum of a Hilbert space and a Banach space without nontrivial -summand vectors. As a consequence, we generalize some results and we obtain intrinsic characterizations of real Hilbert spaces.