International Journal of Mathematics and Mathematical Sciences
Volume 2012 (2012), Article ID 920607, 6 pages
http://dx.doi.org/10.1155/2012/920607
Research Article

On Almost Orthogonal Frames

Virender,1 A. Zothansanga,2 and S. K. Kaushik3

1Department of Mathematics, Ramjas College, University of Delhi, Delhi 110 007, India
2Department of Mathematics, University of Delhi, Delhi 110 007, India
3Department of Mathematics, Kirori Mal College, University of Delhi, Delhi 110 007, India

Received 30 March 2012; Revised 14 May 2012; Accepted 22 May 2012

Academic Editor: Ricardo Estrada

Copyright © 2012 Virender et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Almost orthogonal frames have been introduced and studied. It has been proved that a bounded almost orthogonal frame satisfies Feichtinger conjecture. Also, we prove that a bounded almost orthogonal frame contains a Riesz basis.