{ "id": "2401.05243", "version": "v1", "published": "2024-01-10T16:15:11.000Z", "updated": "2024-01-10T16:15:11.000Z", "title": "Frame-like Fourier expansions for finite Borel measures on $\\mathbb{R}$", "authors": [ "Chad Berner" ], "categories": [ "math.FA" ], "abstract": "It is known that if a finite Borel measure $\\mu$ on $[0,1)$ possesses a frame of exponential functions for $L^{2}(\\mu)$, then $\\mu$ is of pure type. In this paper, we prove the existence of a class of finite Borel measures $\\mu$ on $[0,1)$ that are not of pure type that possess frame-like Fourier expansions for $L^{2}(\\mu)$. We also show properties and classifications of certain measures possessing this type of Fourier expansion. Additionally, we establish a frame-like Fourier expansion for $L^{2}(\\mu)$ where $\\mu$ is a singular Borel probability measure on $\\mathbb{R}$. Finally, we show measures $\\mu$ on $[0,1)$ that possess these frame-like Fourier expansions for $L^{2}(\\mu)$ have all $f\\in L^{2}(\\mu)$ as $L^{2}(\\mu)$ limits of harmonic functions with frame-like coefficients. We also discuss when the inner products of these expansions coincide with model spaces and subspaces of harmonic functions on the disk.", "revisions": [ { "version": "v1", "updated": "2024-01-10T16:15:11.000Z" } ], "analyses": { "subjects": [ "42A16", "42A20", "42C15", "46C07" ], "keywords": [ "finite borel measure", "pure type", "harmonic functions", "singular borel probability measure", "possess frame-like fourier expansions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }