English

A Helson-Szeg\"o theorem for subdiagonal subalgebras with applications to Toeplitz operators

Operator Algebras 2013-01-30 v1 Functional Analysis

Abstract

We formulate and establish a noncommutative version of the well known Helson-Szego theorem about the angle between past and future for subdiagonal subalgebras. We then proceed to use this theorem to characterise the symbols of invertible Toeplitz operators on the noncommutative Hardy spaces associated to subdiagonal subalgebras.

Keywords

Cite

@article{arxiv.1301.6863,
  title  = {A Helson-Szeg\"o theorem for subdiagonal subalgebras with applications to Toeplitz operators},
  author = {Louis E Labuschagne and Quanhua Xu},
  journal= {arXiv preprint arXiv:1301.6863},
  year   = {2013}
}