{ "id": "1804.04510", "version": "v1", "published": "2018-04-11T12:40:54.000Z", "updated": "2018-04-11T12:40:54.000Z", "title": "Riesz transforms on solvable extensions of stratified groups", "authors": [ "Alessio Martini", "Maria Vallarino" ], "comment": "20 pages. arXiv admin note: text overlap with arXiv:1504.03862", "categories": [ "math.FA", "math.AP", "math.CA", "math.DG" ], "abstract": "Let $G = N \\rtimes A$, where $N$ is a stratified group and $A = \\mathbb{R}$ acts on $N$ via automorphic dilations. Homogeneous sub-Laplacians on $N$ and $A$ can be lifted to left-invariant operators on $G$ and their sum is a sub-Laplacian $\\Delta$ on $G$. Here we prove weak type $(1,1)$, $L^p$-boundedness for $p \\in (1,2]$ and $H^1 \\to L^1$ boundedness of the Riesz transforms $Y \\Delta^{-1/2}$ and $Y \\Delta^{-1} Z$, where $Y$ and $Z$ are any horizontal left-invariant vector fields on $G$, as well as the corresponding dual boundedness results. At the crux of the argument are large-time bounds for spatial derivatives of the heat kernel, which are new when $\\Delta$ is not elliptic.", "revisions": [ { "version": "v1", "updated": "2018-04-11T12:40:54.000Z" } ], "analyses": { "subjects": [ "22E30", "42B20", "42B30" ], "keywords": [ "riesz transforms", "stratified group", "solvable extensions", "horizontal left-invariant vector fields", "corresponding dual boundedness results" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }