Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9503206 | Journal of Mathematical Analysis and Applications | 2005 | 6 Pages |
Abstract
Let X be a real Banach space. We prove that the existence of an injective, positive, symmetric and not strictly singular operator from X into its dual implies that either X admits an equivalent Hilbertian norm or it contains a nontrivially complemented subspace which is isomorphic to a Hilbert space. We also treat the nonsymmetric case.
Related Topics
Physical Sciences and Engineering
Mathematics
Analysis
Authors
Dimosthenis Drivaliaris, Nikos Yannakakis,