{ "id": "1909.03945", "version": "v1", "published": "2019-09-09T15:49:12.000Z", "updated": "2019-09-09T15:49:12.000Z", "title": "The Fourier transform of thick distributions", "authors": [ "Ricardo Estrada", "Jasson Vindas", "Yunyun Yang" ], "comment": "21 pages", "categories": [ "math.FA" ], "abstract": "We first construct a space of test functions $\\mathcal{W}\\left( \\mathbb{R}_{\\text{c}}^{n}\\right) $ defined in $\\mathbb{R}_{\\text{c}} ^{n}=\\mathbb{R}^{n}\\cup\\left\\{ \\mathbf{\\infty}\\right\\} ,$ the one point compactification of $\\mathbb{R}^{n},$ that have a thick type behavior at infinity of special logarithmic type and its dual space $\\mathcal{W}^{\\prime }\\left( \\mathbb{R}_{\\text{c}}^{n}\\right) ,$ the space of $sl-$thick distributions. We show that there is a canonical projection of $\\mathcal{W} ^{\\prime}\\left( \\mathbb{R}_{\\text{c}}^{n}\\right) $ onto $\\mathcal{S} ^{\\prime}\\left( \\mathbb{R}^{n}\\right) .$ We study several $sl-$thick distributions and consider operations in $\\mathcal{W}^{\\prime}\\left( \\mathbb{R}_{\\text{c}}^{n}\\right) .$ We define and study the Fourier transform of thick test functions of $\\mathcal{S}_{\\ast}\\left( \\mathbb{R}^{n}\\right) $ and thick tempered functions of $\\mathcal{S}_{\\ast}^{\\prime}\\left( \\mathbb{R}^{n}\\right) .$ We construct isomorphisms \\[ \\mathcal{F}_{\\ast}:\\mathcal{S}_{\\ast}^{\\prime}\\left( \\mathbb{R}^{n}\\right) \\longrightarrow\\mathcal{W}^{\\prime}\\left( \\mathbb{R}_{\\text{c}}^{n}\\right) \\,, \\] \\[ \\mathcal{F}^{\\ast}:\\mathcal{W}^{\\prime}\\left( \\mathbb{R}_{\\text{c}} ^{n}\\right) \\longrightarrow\\mathcal{S}_{\\ast}^{\\prime}\\left( \\mathbb{R} ^{n}\\right) \\,, \\] that extend the Fourier transform of tempered distributions, namely, $\\Pi\\mathcal{F}_{\\ast}=\\mathcal{F}\\Pi$ and $\\Pi\\mathcal{F}^{\\ast} =\\mathcal{F}\\Pi,$ where $\\Pi$ are the canonical projections of $\\mathcal{S} _{\\ast}^{\\prime}\\left( \\mathbb{R}^{n}\\right) $ or $\\mathcal{W}^{\\prime }\\left( \\mathbb{R}_{\\text{c}}^{n}\\right) $ onto $\\mathcal{S}^{\\prime}\\left( \\mathbb{R}^{n}\\right) .$ We find the Fourier transform of several finite part regularizations and of general thick delta functions.", "revisions": [ { "version": "v1", "updated": "2019-09-09T15:49:12.000Z" } ], "analyses": { "subjects": [ "46F10", "42B10" ], "keywords": [ "fourier transform", "thick distributions", "general thick delta functions", "thick type behavior", "special logarithmic type" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable" } } }