{ "id": "2004.12947", "version": "v1", "published": "2020-04-27T17:04:46.000Z", "updated": "2020-04-27T17:04:46.000Z", "title": "Subexponential decay and regularity estimates for eigenfunctions of localization operators", "authors": [ "Federico Bastianoni", "Nenad Teofanov" ], "comment": "29 pages", "categories": [ "math.FA" ], "abstract": "We consider time-frequency localization operators $A_a^{\\varphi_1,\\varphi_2}$ with symbols $a$ in the wide weighted modulation space $ M^\\infty_{w}(\\mathbb{R}^{2d})$, and windows $ \\varphi_1, \\varphi_2 $ in the Gelfand-Shilov space $\\mathcal{S}^{\\left(1\\right)}(\\mathbb{R}^{d})$. If the weights under consideration are of ultra-rapid growth, we prove that the eigenfunctions of $A_a^{\\varphi_1,\\varphi_2}$ have appropriate subexponential decay in phase space, i.e. that they belong to the Gefand-Shilov space $ \\mathcal{S}^{(\\gamma)} (\\mathbb{R}^{2d}) $, where the parameter $\\gamma \\geq 1 $ is related to the growth of the considered weight. An important role is played by $\\tau$-pseudodifferential operators $\\mathrm{Op}_\\tau(\\sigma)$. In that direction we show convenient continuity properties of $\\mathrm{Op}_\\tau(\\sigma)$ when acting on weighted modulation spaces. Furthermore, we prove subexponential decay and regularity properties of the eigenfunctions of $\\mathrm{Op}_\\tau(\\sigma)$ when the symbol $\\sigma$ belongs to a modulation space with appropriately chosen weight functions. As a tool we also prove new convolution relations for (quasi-)Banach weighted modulation spaces.", "revisions": [ { "version": "v1", "updated": "2020-04-27T17:04:46.000Z" } ], "analyses": { "subjects": [ "47G30", "47B10", "46F05", "35S05" ], "keywords": [ "regularity estimates", "eigenfunctions", "wide weighted modulation space", "banach weighted modulation spaces", "appropriately chosen weight functions" ], "note": { "typesetting": "TeX", "pages": 29, "language": "en", "license": "arXiv", "status": "editable" } } }