{ "id": "1409.3017", "version": "v1", "published": "2014-09-10T10:49:42.000Z", "updated": "2014-09-10T10:49:42.000Z", "title": "Composition Operators on Bohr-Bergman Spaces of Dirichlet Series", "authors": [ "Maxime Bailleul", "Ole Fredrik Brevig" ], "categories": [ "math.FA" ], "abstract": "For $\\alpha \\in \\mathbb{R}$, let $\\mathscr{D}_\\alpha$ denote the scale of Hilbert spaces consisting of Dirichlet series $f(s) = \\sum_{n=1}^\\infty a_n n^{-s}$ that satisfy $\\sum_{n=1}^\\infty |a_n|^2/[d(n)]^\\alpha < \\infty$. The Gordon--Hedenmalm Theorem on composition operators for $\\mathscr{H}^2=\\mathscr{D}_0$ is extended to the Bergman case $\\alpha>0$. These composition operators are generated by functions of the form $\\Phi(s) = c_0 s + \\varphi(s)$, where $c_0$ is a nonnegative integer and $\\varphi(s)$ is a Dirichlet series with certain convergence and mapping properties. For the operators with $c_0=0$ a new phenomenon is discovered: If $0 < \\alpha < 1$, the space $\\mathscr{D}_\\alpha$ is mapped by the composition operator into a smaller space in the same scale. When $\\alpha > 1$, the space $\\mathscr{D}_\\alpha$ is mapped into a larger space in the same scale. Moreover, a partial description of the composition operators on the Dirichlet--Bergman spaces $\\mathscr{A}^p$ for $1 \\leq p < \\infty$ are obtained, in addition to new partial results for composition operators on the Dirichlet--Hardy spaces $\\mathscr{H}^p$ when $p$ is an odd integer.", "revisions": [ { "version": "v1", "updated": "2014-09-10T10:49:42.000Z" } ], "analyses": { "subjects": [ "47B33", "30B50" ], "keywords": [ "composition operator", "dirichlet series", "bohr-bergman spaces", "dirichlet-bergman spaces", "partial description" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1409.3017B" } } }