English

Which weighted composition operators are hyponormal on the Hardy and weighted Bergman spaces?

Functional Analysis 2016-02-01 v2

Abstract

In this paper, we study hyponormal weighed composition operators on the Hardy and weighted Bergman spaces. For functions ψA(D)\psi \in A(\mathbb{D}) which are not the zero function, we characterize all hyponormal compact weighted composition operators Cψ,φC_{\psi,\varphi} on H2H^{2} and Aα2A^{2}_{\alpha}. Next, we show that for φ\mboxLFT(D)\varphi \in \mbox{LFT}(\mathbb{D}), if CφC_{\varphi} is hyponormal on H2H^{2} or Aα2A^{2}_{\alpha}, then φ(z)=λz\varphi(z)=\lambda z, where λ1|\lambda| \leq 1 or φ\varphi is a hyperbolic non-automorphism with φ(0)=0\varphi(0)=0 and such that φ\varphi has another fixed point in D\partial \mathbb{D}. After that, we find the essential spectral radius of CφC_{\varphi} on H2H^{2} and Aα2A^{2}_{\alpha}, when φ\varphi has a Denjoy-Wolff point ζD\zeta \in \partial \mathbb{D}. Finally, descriptions of spectral radii are provided for some hyponormal weighted composition operators on H2H^{2} and Aα2A^{2}_{\alpha}.

Keywords

Cite

@article{arxiv.1505.00684,
  title  = {Which weighted composition operators are hyponormal on the Hardy and weighted Bergman spaces?},
  author = {Mahsa Fatehi and Mahmood Haji Shaabani},
  journal= {arXiv preprint arXiv:1505.00684},
  year   = {2016}
}