English

Parseval frames for ICC groups

Functional Analysis 2008-11-21 v2 Operator Algebras

Abstract

We analyze Parseval frames generated by the action of an ICC group on a Hilbert space. We parametrize the set of all such Parseval frames by operators in the commutant of the corresponding representation. We characterize when two such frames are strongly disjoint. We prove an undersampling result showing that if the representation has a Parseval frame of norm 1N\frac{1}{\sqrt{N}}, the Hilbert space is spanned by an orthonormal basis generated by a subgroup. As applications we obtain some sufficient conditions under which a unitary representation admits a Parseval frame which is spanned by an Riesz sequences generated by a subgroup. In particular, every subrepresentation of the left regular representation of a free group has this property.

Keywords

Cite

@article{arxiv.0808.2944,
  title  = {Parseval frames for ICC groups},
  author = {Dorin Ervin Dutkay and Deguang Han and Gabriel Picioroaga},
  journal= {arXiv preprint arXiv:0808.2944},
  year   = {2008}
}
R2 v1 2026-06-21T11:12:43.567Z