English

On various R-duals and the duality principle

Functional Analysis 2020-09-11 v1

Abstract

The duality principle states that a Gabor system is a frame if and only if the corresponding adjoint Gabor system is a Riesz sequence. In general Hilbert spaces and without the assumption of any particular structure, Casazza, Kutyniok and Lammers have introduced the so-called R-duals that also lead to a characterization of frames in terms of associated Riesz sequences; however, it is still an open question whether this abstract theory is a generalization of the duality principle. In this paper we prove that a modified version of the R-duals leads to a generalization of the duality principle that keeps all the attractive properties of the R-duals. In order to provide extra insight into the relations between a given sequence and its R-duals, we characterize all the types of R-duals that are available in the literature for the special case where the underlying sequence is a Riesz basis.

Keywords

Cite

@article{arxiv.1509.06263,
  title  = {On various R-duals and the duality principle},
  author = {Diana T. Stoeva and Ole Christensen},
  journal= {arXiv preprint arXiv:1509.06263},
  year   = {2020}
}
R2 v1 2026-06-22T11:01:44.295Z