{ "id": "2104.10912", "version": "v1", "published": "2021-04-22T07:41:48.000Z", "updated": "2021-04-22T07:41:48.000Z", "title": "New parameters and Lebesgue-type estimates in greedy approximation", "authors": [ "Fernando Albiac", "Jose L. Ansorena", "Pablo M. Berna" ], "categories": [ "math.FA" ], "abstract": "The purpose of this paper is to quantify the size of the Lebesgue constants $(L_m)_{m=1}^{\\infty}$ associated with the thresholding greedy algorithm in terms of a new generation of parameters that modulate accurately some features of a general basis. This fine-tuning of constants allows us to provide an answer to the question raised by Temlyakov in 2011 to find a natural sequence of greedy-type parameters for arbitrary bases in Banach (or quasi-Banach) spaces which combined linearly with the sequence of unconditionality parameters $(k_m)_{m=1}^{\\infty}$ determines the growth of $(L_m)_{m=1}^{\\infty}$. Multiple theoretical applications and computational examples complement our study.", "revisions": [ { "version": "v1", "updated": "2021-04-22T07:41:48.000Z" } ], "analyses": { "subjects": [ "41A65", "41A25", "41A46", "41A17", "46B15" ], "keywords": [ "greedy approximation", "lebesgue-type estimates", "computational examples complement", "thresholding greedy algorithm", "general basis" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }