{ "id": "1403.4168", "version": "v4", "published": "2014-03-17T17:02:36.000Z", "updated": "2016-07-14T02:50:46.000Z", "title": "Fourier and Beyond: Invariance Properties of a Family of Integral Transforms", "authors": [ "Cameron L. Williams", "Bernhard G. Bodmann", "Donald J. Kouri" ], "comment": "14 pages", "categories": [ "math.FA", "math.CA" ], "abstract": "The Fourier transform is typically seen as closely related to the additive group of real numbers, its characters and its Haar measure. In this paper, we propose an alternative viewpoint; the Fourier transform can be uniquely characterized by an intertwining relation with dilations and by having a Gaussian as an eigenfunction. This broadens the perspective to an entire family of Fourier-like transforms that are uniquely identified by the same dilation property and having Gaussian-like functions as eigenfunctions. We show that these transforms share many properties with the Fourier transform, particularly unitarity, periodicity and eigenvalues. We also establish short-time analogues of these transforms and show a reconstruction property and an orthogonality relation for the short-time transforms.", "revisions": [ { "version": "v3", "updated": "2014-07-09T03:41:29.000Z", "abstract": "This paper presents a family of transforms which share many properties with the Fourier transform. We prove that these transforms are isometries on $L^2(\\mathbb{R})$ and have the same scaling property. The transforms can be chosen to leave Gaussian-like functions invariant. We also establish short-time analogs of these transforms.", "comment": "15 pages", "journal": null, "doi": null }, { "version": "v4", "updated": "2016-07-14T02:50:46.000Z" } ], "analyses": { "keywords": [ "invariance properties", "integral transforms", "leave gaussian-like functions invariant", "fourier transform", "establish short-time analogs" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1403.4168W" } } }