{ "id": "1507.08004", "version": "v1", "published": "2015-07-29T01:38:46.000Z", "updated": "2015-07-29T01:38:46.000Z", "title": "Characterizations of Besov and Triebel-Lizorkin Spaces via Averages on Balls", "authors": [ "Feng Dai", "Amiran Gogatishvili", "Dachun Yang", "Wen Yuan" ], "comment": "21 pages, Submitted", "categories": [ "math.CA", "math.FA" ], "abstract": "Let $\\ell\\in\\mathbb{N}$ and $p\\in(1,\\infty]$. In this article, the authors prove that the sequence $\\{f-B_{\\ell,2^{-k}}f\\}_{k\\in\\mathbb{Z}}$ consisting of the differences between $f$ and the ball average $B_{\\ell,2^{-k}}f$ characterizes the Besov space $\\dot B^\\alpha_{p,q}(\\rn)$ with $q\\in (0, \\infty]$ and the Triebel-Lizorkin space $\\dot F^\\alpha_{p,q}(\\rn)$ with $q\\in (1,\\infty]$ when the smoothness order $\\alpha\\in(0,2\\ell)$. More precisely, it is proved that $f-B_{\\ell,2^{-k}}f$ plays the same role as the approximation to the identity $\\varphi_{2^{-k}}\\ast f$ appearing in the definitions of $\\dot B^\\alpha_{p,q}(\\rn)$ and $\\dot F^\\alpha_{p,q}(\\rn)$. The corresponding results for inhomogeneous Besov and Triebel-Lizorkin spaces are also obtained. These results, for the first time, give a way to introduce Besov and Triebel-Lizorkin spaces with any smoothness order in $(0, 2\\ell)$ on spaces of homogeneous type, where $\\ell\\in{\\mathbb N}$.", "revisions": [ { "version": "v1", "updated": "2015-07-29T01:38:46.000Z" } ], "analyses": { "subjects": [ "46E35", "42B25", "42B35" ], "keywords": [ "triebel-lizorkin space", "smoothness order", "characterizations", "ball average", "besov space" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable" } } }