English

The Hardy-Weyl algebra

Operator Algebras 2022-05-05 v1

Abstract

We study the algebra A\mathcal{A} generated by the Hardy operator HH and the operator MxM_x of multiplication by xx on L2[0,1]L^2[0,1]. We call A\mathcal{A} the Hardy-Weyl algebra. We show that its quotient by the compact operators is isomorphic to the algebra of functions that are continuous on Λ\Lambda and analytic on the interior of Λ\Lambda for a planar set Λ\Lambda = [1,0]D(1,1)ˉ[-1,0] \cup \bar{ \mathbb{D}(1,1)}, which we call the lollipop. We find a Toeplitz-like short exact sequence for the CC^*-algebra generated by A\mathcal{A}. We study the operator Z=HMxZ = H - M_x, show that its point spectrum is (1,0]D(1,1)(-1,0] \cup \mathbb{D}(1,1), and that the eigenvalues grow in multiplicity as the points move to 00 from the left.

Keywords

Cite

@article{arxiv.2205.01862,
  title  = {The Hardy-Weyl algebra},
  author = {Jim Agler and John E. McCarthy},
  journal= {arXiv preprint arXiv:2205.01862},
  year   = {2022}
}
R2 v1 2026-06-24T11:06:38.621Z