{ "id": "2305.16068", "version": "v1", "published": "2023-05-25T13:58:29.000Z", "updated": "2023-05-25T13:58:29.000Z", "title": "Optimal Polynomial Approximants in $H^p$", "authors": [ "Raymond Centner", "Raymond Cheng", "Christopher Felder" ], "categories": [ "math.FA", "math.CV" ], "abstract": "This work studies optimal polynomial approximants (OPAs) in the classical Hardy spaces on the unit disk, $H^p$ ($1 < p < \\infty$). In particular, we uncover some estimates concerning the OPAs of degree zero and one. It is also shown that if $f \\in H^p$ is an inner function, or if $p>2$ is an even integer, then the roots of the nontrivial OPA for $1/f$ are bounded from the origin by a distance depending only on $p$. For $p\\neq 2$, these results are made possible by the novel use of a family of inequalities which are derived from a Banach space analogue of the Pythagorean theorem.", "revisions": [ { "version": "v1", "updated": "2023-05-25T13:58:29.000Z" } ], "analyses": { "subjects": [ "30E10", "46E30" ], "keywords": [ "work studies optimal polynomial approximants", "banach space analogue", "hardy spaces", "unit disk", "pythagorean theorem" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }