English

Hilbert-type operator induced by radial weight on Hardy spaces

Complex Variables 2022-08-01 v1

Abstract

We consider the Hilbert-type operator defined by Hω(f)(z)=01f(t)(1z0zBtω(u)du)ω(t)dt, H_{\omega}(f)(z)=\int_0^1 f(t)\left(\frac{1}{z}\int_0^z B^{\omega}_t(u)\,du\right)\,\omega(t)dt, where {Bζω}ζD\{B^{\omega}_\zeta\}_{\zeta\in\mathbb{D}} are the reproducing kernels of the Bergman space Aω2A^2_\omega induced by a radial weight ω\omega in the unit disc D\mathbb{D}. We prove that HωH_{\omega} is bounded on the Hardy space HpH^p, 1<p<1<p<\infty, if and only if \begin{equation} \label{abs1} \sup_{0\le r<1} \frac{\widehat{\omega}(r)}{\widehat{\omega}\left( \frac{1+r}{2}\right)}<\infty, \tag{\dag} \end{equation} and \begin{equation*} \sup\limits_{0<r<1}\left(\int_0^r \frac{1}{\widehat{\omega}(t)^p} dt\right)^{\frac{1}{p}} \left(\int_r^1 \left(\frac{\widehat{\omega}(t)}{1-t}\right)^{p'}\,dt\right)^{\frac{1}{p'}} <\infty, \end{equation*} where ω^(r)=r1ω(s)ds\widehat{\omega}(r)=\int_r^1 \omega(s)\,ds. We also prove that Hω:H1H1H_\omega: H^1\to H^1 is bounded if and only if \eqref{abs1} holds and supr[0,1)ω^(r)1r(0rdsω^(s))<. \sup\limits_{r \in [0,1)} \frac{\widehat{\omega}(r)}{1-r} \left(\int_0^r \frac{ds}{\widehat{\omega}(s)}\right)<\infty. As for the case p=p=\infty, HωH_\omega is bounded from HH^\infty to BMOABMOA, or to the Bloch space, if and only if \eqref{abs1} holds. In addition, we prove that there does not exist radial weights ω\omega such that Hω:HpHpH_{\omega}: H^p \to H^p , 1p<1\le p<\infty, is compact and we consider the action of HωH_{\omega} on some spaces of analytic functions closely related to Hardy spaces.

Keywords

Cite

@article{arxiv.2207.14605,
  title  = {Hilbert-type operator induced by radial weight on Hardy spaces},
  author = {Noel Merchán and José Angel Peláez and Elena de la Rosa},
  journal= {arXiv preprint arXiv:2207.14605},
  year   = {2022}
}