{ "id": "1006.0900", "version": "v2", "published": "2010-06-04T14:17:23.000Z", "updated": "2010-08-25T10:12:18.000Z", "title": "Asymptotics of the L^2 Norm of Derivatives of OPUC", "authors": [ "Andrei Martinez-Finkelshtein", "Barry Simon" ], "comment": "36 pages, no figures. Minor corrections, to appear in the Journal of Approximation Theory", "categories": [ "math.CA" ], "abstract": "We show that for many families of OPUC, one has $||\\varphi'_n||_2/n -> 1$, a condition we call normal behavior. We prove that this implies $|\\alpha_n| -> 0$ and that it holds if the sequence $\\alpha_n$ is in $\\ell^1$. We also prove it is true for many sparse sequences. On the other hand, it is often destroyed by the insertion of a mass point.", "revisions": [ { "version": "v2", "updated": "2010-08-25T10:12:18.000Z" } ], "analyses": { "subjects": [ "42C05", "34D05", "31A99" ], "keywords": [ "asymptotics", "derivatives", "normal behavior", "sparse sequences" ], "note": { "typesetting": "TeX", "pages": 36, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1006.0900M" } } }