Optimal estimates for hyperbolic harmonic mappings in Hardy space

TL;DR

This paper derives sharp inequalities for hyperbolic harmonic mappings in Hardy spaces, extending known results by providing explicit bounds involving hypergeometric and Gamma functions.

Contribution

It introduces optimal estimates for hyperbolic harmonic mappings in Hardy spaces, generalizing previous harmonic mapping results with explicit sharp bounds.

Findings

Established sharp inequalities involving hypergeometric and Gamma functions.

Extended known harmonic mapping results to hyperbolic harmonic mappings.

Provided explicit bounds depending on the point in the unit ball.

Abstract

Assume that $p\in(1,\infty]$ and $u=P_{h}[\phi]$, where $\phi\in L^{p}(\mathbb{S}^{n-1},\mathbb{R}^{n})$. Then for any $x\in \mathbb{B}^{n}$, we obtain the sharp inequalities $$ |u(x)|\leq \frac{\mathbf{C}_{q}^{\frac{1}{q}}(x)}{(1-|x|^2)^{\frac{n-1 }{p}}} \|\phi\|_{L^{p}} \quad\text{and}\quad |u(x)|\leq \frac{\mathbf{C}_{q}^{\frac{1}{q}} }{(1-|x|^2)^{\frac{n-1 }{p}}} \|\phi\|_{L^{p} } $$ for some function $\mathbf{C}_{q}(x)$ and constant $\mathbf{C}_{q}$ in terms of Gauss hypergeometric and Gamma functions, where $q$ is the conjugate of $p$. This result generalize and extend some known result from harmonic mapping theory ([5, Theorems 1.1 and 1.2] and [1, Proposition 6.16]).