1. Istituto di Matematica di Ingegneria, Piazzale Kennedy Pad. D, 16129, Genova, Italy 2. Dipartimento Di Matematica Applicata “G. Sansone”, Via Di S. Marta 3, 50139, Firenze, Italy
Abstract:
Some results on existence of norm one projections onto hyperplanes in spaces with a Schauder basis are given. Possible characterizations of Hilbert spaces using this property are also discussed.