{ "id": "1602.00044", "version": "v1", "published": "2016-01-30T00:26:42.000Z", "updated": "2016-01-30T00:26:42.000Z", "title": "Bounds for Extreme Zeros of Quasi-orthogonal Ultraspherical Polynomials", "authors": [ "Kathy Driver", "Martin E. Muldoon" ], "comment": "10 pages, 1 figure", "categories": [ "math.CA" ], "abstract": "We discuss and compare upper and lower bounds obtained by two different methods for the positive zero of the ultraspherical polynomial $C_{n}^{(\\lambda)}$ that is greater than $1$ when $-3/2 < \\lambda < -1/2.$ Our first approach uses mixed three term recurrence relations and interlacing of zeros while the second approach uses a method going back to Euler and Rayleigh and already applied to Bessel functions and Laguerre and $q$-Laguerre polynomials. We use the bounds obtained by the second method to simplify the proof of the interlacing of the zeros of $(1-x^2)C_{n}^{(\\lambda)}$ and $C_{n+1}^{(\\lambda)}$, for $-3/2 < \\lambda < \\infty$.", "revisions": [ { "version": "v1", "updated": "2016-01-30T00:26:42.000Z" } ], "analyses": { "subjects": [ "33C45" ], "keywords": [ "quasi-orthogonal ultraspherical polynomials", "extreme zeros", "term recurrence relations", "second method", "first approach" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160200044D" } } }