English

A Beurling Theorem for almost-invariant subspaces of the shift operator

Functional Analysis 2019-05-21 v2 Complex Variables

Abstract

A complete characterization of nearly-invariant subspaces of finite defect for the backward shift operator acting on the Hardy space is provided in the spirit of Hitt and Sarason's theorem. As a corollary we describe the almost-invariant subspaces for the shift and its adjoint.

Keywords

Cite

@article{arxiv.1905.06652,
  title  = {A Beurling Theorem for almost-invariant subspaces of the shift operator},
  author = {Isabelle Chalendar and Eva A. Gallardo-Gutiérrez and Jonathan R. Partington},
  journal= {arXiv preprint arXiv:1905.06652},
  year   = {2019}
}

Comments

11 pages. Revised version. To appear in J. Operator Theory

R2 v1 2026-06-23T09:08:30.808Z