arXiv subjects

L. Gavruta

Publications and source records attributed to L. Gavruta.

3 recordsLinked to original sources

arXiv2015

Some properties of operator-valued frames

Operator-valued frames (or g-frames) are generalizations of frames and fusion frames and have been used in packets encoding, quantum computing, theory of coherent states and more. In this paper, we give a new formula for operator-valued frames for finite dimensional Hilbert spaces. As an application, we derive in a simple manner a recent result of A. Najati concerning the approximation of g-frames by Parseval ones. We obtain also some results concerning the best approximation of operator-valued frames by its alternate duals, with optimal estimates.

math.FA↗

arXiv2014

Two classes of Meir-Keeler contractions

In the present paper, we prove that Z-contractions and weakly type contractions are actually Meir-Keeler contractions.

math.FA↗

arXiv2014

Frames for compressed sensing using coherence

We give some new results on sparse signal recovery in the presence of noise, for weighted spaces. Traditionally, were used dictionaries that have the norm equal to 1, but, for random dictionaries this condition is rarely satisfied. Moreover, we give better estimations then the ones given recently by Cai, Wang and Xu.

math.FA↗