English

An inequality associated with $\mathcal{Q}_p$ functions

Complex Variables 2019-01-07 v2

Abstract

The M\"obius invariant space Qp\mathcal{Q}_p, 0<p<0<p<\infty, consists of functions ff which are analytic in the open unit disk D\mathbb{D} with fQp=f(0)+supw\D(\Df(z)2(1σw(z)2)pdA(z))1/2<, \|f\|_{\mathcal{Q}_p}=|f(0)|+\sup_{w\in \D} \left(\int_\D |f'(z)|^2(1-|\sigma_w(z)|^2)^p dA(z)\right)^{1/2}<\infty, where σw(z)=(wz)/(1wz)\sigma_w(z)=(w-z)/(1-\overline{w}z) and dAdA is the area measure on D\mathbb{D}. It is known that the following inequality f(0)+supw\D(\Df(z)f(w)1wz2(1σw(z)2)pdA(z))1/2fQp |f(0)|+\sup_{w\in \D} \left(\int_\D \left|\frac{f(z)-f(w)}{1-\overline{w}z}\right|^2 (1-|\sigma_w(z)|^2)^p dA(z)\right)^{1/2} \lesssim \|f\|_{\mathcal{Q}_p} played a key role to characterize multipliers and certain Carleson measures for Qp\mathcal{Q}_p spaces. The converse of the inequality above is a conjectured-inequality in [14]. In this paper, we show that this conjectured-inequality is true for p>1p>1 and it does not hold for 0<p10<p\leq 1.

Keywords

Cite

@article{arxiv.1810.05901,
  title  = {An inequality associated with $\mathcal{Q}_p$ functions},
  author = {Guanlong Bao and Fangqin Ye},
  journal= {arXiv preprint arXiv:1810.05901},
  year   = {2019}
}

Comments

The paper has been withdrawn by the authors. The aim of this paper is to answer a question from 2008. But the main auxiliary result in this paper is not new

R2 v1 2026-06-23T04:38:40.082Z