English

Iterated Aluthge transforms of some composition operators on weighted Bergman spaces

Functional Analysis 2026-05-01 v1

Abstract

In this paper, we compute the iterated Aluthge transforms Cϕ~(n)\widetilde{C_\phi}^{(n)} of the composition operator CϕC_\phi on the weighted Bergman spaces Aα2(D)\mathcal{A}_\alpha^2(\mathbb{D}), where ϕ(z)=az+(1a)\phi(z)=az+(1-a) for 0<a<10<a<1. Also, we obtain the norm and numerical radius of Cϕ~(n)\widetilde{C_\phi}^{(n)} on Aα2(D)\mathcal{A}_\alpha^2(\mathbb{D}). We establish that Cϕ~(n)\widetilde{C_\phi}^{(n)} converges in the strong operator topology on Aα2(D)\mathcal{A}_\alpha^2(\mathbb{D}). The purpose of this paper is to examine the results of \cite{jung2015iterated} for the weighted Bergman spaces Aα2(D)\mathcal{A}_\alpha^2(\mathbb{D}). Additionally, by using the iterated Aluthge transforms of CϕC_\phi^* on Aα2(D)\mathcal{A}_\alpha^2(\mathbb{D}), we derive the iterated Aluthge transforms of CσC_\sigma, where σ(z)=az(1a)z+1\displaystyle\sigma(z)=\frac{az}{-(1-a)z+1} for 0<a<10<a<1, on some weighted Hardy space H2(βα)H^2(\beta_\alpha) and study its convergence. Finally, we raise some questions that emerge from these findings.

Keywords

Cite

@article{arxiv.2604.27762,
  title  = {Iterated Aluthge transforms of some composition operators on weighted Bergman spaces},
  author = {Sudeshna Lahiri and Sarita Ojha and Riddhick Birbonshi},
  journal= {arXiv preprint arXiv:2604.27762},
  year   = {2026}
}