Characterizations of inner product spaces by orthogonal vectors. Issue 1 (2006)

• Record Type: Journal Article
• Authors: Baronti Baronti, Marco Marco; Casini Casini, Emanuele Emanuele
• Other Names: Appell Appell Jürgen Jürgen Academic Editor.
• Is Part Of: Journal of function spaces and applications. Volume 4:Issue 1(2006)
• Page Start: 1
• Page End: 6
• Publication Date: 2006
• Subjects: Orthogonality -- Characterizations of inner product spaces; Function spaces -- Periodicals; 515.73
• DOI: 10.1155/2006/521425
• Languages: English
• ISSNs: 0972-6802

Abstract

Abstract : Let X be a real normed space with unit closed ball B . We prove that X is an inner product space if and only if it is true that whenever x, y are points in ∂ B such that the line through x and y supports 2 2 B then x ⊥ y in the sense of Birkhoff.