{ "id": "1804.10984", "version": "v1", "published": "2018-04-29T19:57:40.000Z", "updated": "2018-04-29T19:57:40.000Z", "title": "Riesz bases from orthonormal bases by replacement", "authors": [ "Laura De Carli", "Julian Edward" ], "categories": [ "math.FA" ], "abstract": "Given an orthonormal basis $ {\\mathcal V}= \\{v_j\\} _{j\\in N}$ in a separable Hilbert space $H$ and a set of unit vectors $ {\\mathcal B}=\\{w_j\\}_{j\\in N}$, we consider the sets $ {\\mathcal B}_N$ obtained by replacing the vectors $v_1, ...,\\, v_N$ with vectors $w_1,\\, ...,\\, w_N$. We show necessary and sufficient conditions that ensure that the sets $ {\\mathcal B}_N$ are Riesz bases of $H$ and we estimate the frame constants of the $ {\\mathcal B}_N$. Then, we prove conditions that ensure that $ {\\mathcal B}$ is a Riesz basis. Applications to the construction of exponential bases on domains of $ R^d$ are also presented.", "revisions": [ { "version": "v1", "updated": "2018-04-29T19:57:40.000Z" } ], "analyses": { "keywords": [ "riesz basis", "orthonormal basis", "replacement", "unit vectors", "sufficient conditions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }