arXiv Analytics

Sign in

arXiv:0908.1942 [math.LO]AbstractReferencesReviewsResources

Orthonormal bases of Hilbert spaces

Ilijas Farah

Published 2009-08-13, updated 2009-08-15Version 2

I prove that a Hilbert space has the property that each of its dense (not necessarily closed) subspaces contains an orthoormal basis if and only if it is separable.

Comments: The main result of the note has been known. See Orthonormal bases and quasi-splitting subspaces in pre-Hilbert spaces D. Buhagiar, E. Chetcuti, H. Weber, J. Math. Anal. Appl., 345 (2008) 725-730. and the references thereof. Thanks to Nigel Kalton to pointing this out
Categories: math.LO, math.FA
Related articles: Most relevant | Search more
arXiv:1010.2243 [math.LO] (Published 2010-10-11)
Definable Operators on Hilbert Spaces
arXiv:math/0411625 [math.LO] (Published 2004-11-28)
Hilbert spaces with generic groups of automorphisms
arXiv:1102.2454 [math.LO] (Published 2011-02-11, updated 2011-06-06)
Model Theory of a Hilbert Space Expanded with an Unbounded Closed Selfadjoint Operator