{ "id": "1506.03397", "version": "v1", "published": "2015-06-10T17:09:32.000Z", "updated": "2015-06-10T17:09:32.000Z", "title": "Characterization of $1$-almost greedy bases", "authors": [ "F. Albiac", "J. L. Ansorena" ], "categories": [ "math.FA" ], "abstract": "This article closes the cycle of characterizations of greedy-like bases in the isometric case initiated in [F. Albiac and P. Wojtaszczyk, Characterization of $1$-greedy bases, J. Approx. Theory 138 (2006)] with the characterization of $1$-greedy bases and continued in [F. Albiac and J. L. Ansorena, Characterization of $1$-quasi-greedy bases, arXiv:1504.04368v1 [math.FA] (2015)] with the characterization of $1$-quasi-greedy bases. Here we settle the problem of providing a characterization of $1$-almost greedy bases in (real or complex) Banach spaces. We show that a (semi-normalized) basis in a Banach space is almost-greedy with almost greedy constant equal to $1$ if and only if it is quasi-greedy with suppression quasi-greedy constant equal to $1$ and has Property (A).", "revisions": [ { "version": "v1", "updated": "2015-06-10T17:09:32.000Z" } ], "analyses": { "subjects": [ "46B15", "41A65", "46B15" ], "keywords": [ "characterization", "suppression quasi-greedy constant equal", "quasi-greedy bases", "banach space", "isometric case" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150603397A" } } }