{ "id": "2008.11553", "version": "v1", "published": "2020-08-26T13:34:47.000Z", "updated": "2020-08-26T13:34:47.000Z", "title": "Norm estimates of the partial derivatives for harmonic and harmonic elliptic mappings", "authors": [ "Sh. Chen", "S. Ponnusamy", "X. Wang" ], "comment": "7 pages", "categories": [ "math.CV" ], "abstract": "Let $f = P[F]$ denote the Poisson integral of $F$ in the unit disk $\\mathbb{D}$ with $F$ being absolutely continuous in the unit circle $\\mathbb{T}$ and $\\dot{F}\\in L_p(0, 2\\pi)$, where $\\dot{F}(e^{it})=\\frac{d}{dt} F(e^{it})$ and $p\\geq 1$. Recently, the author in \\cite{Zhu} proved that $(1)$ if $f$ is a harmonic mapping and $1\\leq p< 2$, then $f_{z}$ and $\\overline{f_{\\overline{z}}}\\in \\mathcal{B}^{p}(\\mathbb{D}),$ the classical Bergman spaces of $\\mathbb{D}$ \\cite[Theorem 1.2]{Zhu}; $(2)$ if $f$ is a harmonic quasiregular mapping and $1\\leq p\\leq \\infty$, then $f_{z},$ $\\overline{f_{\\overline{z}}}\\in \\mathcal{H}^{p}(\\mathbb{D}),$ the classical Hardy spaces of $\\mathbb{D}$ \\cite[Theorem 1.3]{Zhu}. These are the main results in \\cite{Zhu}. The purpose of this paper is to generalize these two results. First, we prove that, under the same assumptions, \\cite[Theorem 1.2]{Zhu} is true when $1\\leq p< \\infty$. Also, we show that \\cite[Theorem 1.2]{Zhu} is not true when $p=\\infty$. Second, we demonstrate that \\cite[Theorem 1.3]{Zhu} still holds true when the assumption $f$ being a harmonic quasiregular mapping is replaced by the weaker one $f$ being a harmonic elliptic mapping.", "revisions": [ { "version": "v1", "updated": "2020-08-26T13:34:47.000Z" } ], "analyses": { "subjects": [ "30C62", "31A05", "30H10", "30H20" ], "keywords": [ "harmonic elliptic mapping", "partial derivatives", "norm estimates", "harmonic quasiregular mapping", "classical hardy spaces" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable" } } }