English

Fredholmness and compactness of truncated Toeplitz and Hankel operators

Complex Variables 2022-02-28 v1

Abstract

We prove the spectral mapping theorem σe(Aϕ)=ϕ(σe(Az))\sigma_e(A_\phi) = \phi(\sigma_e(A_z)) for the Fredholm spectrum of a truncated Toeplitz operator AϕA_\phi with symbol ϕ\phi in the Sarason algebra C+HC+H^\infty acting on a coinvariant subspace KθK_\theta of the Hardy space H2H^2. Our second result says that a truncated Hankel operator on the subspace KθK_\theta generated by a one-component inner function θ\theta is compact if and only if it has a continuous symbol. We also suppose a description of truncated Toeplitz and Hankel operators in Schatten classes SpS^p.

Keywords

Cite

@article{arxiv.1407.3466,
  title  = {Fredholmness and compactness of truncated Toeplitz and Hankel operators},
  author = {R. V. Bessonov},
  journal= {arXiv preprint arXiv:1407.3466},
  year   = {2022}
}

Comments

10 pages, 1 conjecture