pith. sign in

arxiv: 1810.05901 · v2 · pith:NI2N7QWFnew · submitted 2018-10-13 · 🧮 math.CV

An inequality associated with mathcal{Q}_p functions

classification 🧮 math.CV
keywords mathcalinequalityleftrightsigmaconjectured-inequalityfunctionsinfty
0
0 comments X
read the original abstract

The M\"obius invariant space $\mathcal{Q}_p$, $0<p<\infty$, consists of functions $f$ which are analytic in the open unit disk $\mathbb{D}$ with $$ \|f\|_{\mathcal{Q}_p}=|f(0)|+\sup_{w\in \D} \left(\int_\D |f'(z)|^2(1-|\sigma_w(z)|^2)^p dA(z)\right)^{1/2}<\infty, $$ where $\sigma_w(z)=(w-z)/(1-\overline{w}z)$ and $dA$ is the area measure on $\mathbb{D}$. It is known that the following inequality $$ |f(0)|+\sup_{w\in \D} \left(\int_\D \left|\frac{f(z)-f(w)}{1-\overline{w}z}\right|^2 (1-|\sigma_w(z)|^2)^p dA(z)\right)^{1/2} \lesssim \|f\|_{\mathcal{Q}_p} $$ played a key role to characterize multipliers and certain Carleson measures for $\mathcal{Q}_p$ 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 $p>1$ and it does not hold for $0<p\leq 1$.

This paper has not been read by Pith yet.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.