{ "id": "0903.3071", "version": "v1", "published": "2009-03-18T01:28:45.000Z", "updated": "2009-03-18T01:28:45.000Z", "title": "Necessary and sufficient conditions for a function involving divided differences of the di- and tri-gamma functions to be completely monotonic", "authors": [ "Feng Qi", "Bai-Ni Guo" ], "comment": "14 pages", "categories": [ "math.CA" ], "abstract": "In the present paper, necessary and sufficient conditions are established for a function involving divided differences of the digamma and trigamma functions to be completely monotonic. Consequently, necessary and sufficient conditions are derived for a function involving the ratio of two gamma functions to be logarithmically completely monotonic, and some double inequalities are deduced for bounding divided differences of polygamma functions.", "revisions": [ { "version": "v1", "updated": "2009-03-18T01:28:45.000Z" } ], "analyses": { "subjects": [ "26A48", "33B15", "26A51", "26D10", "65R10" ], "keywords": [ "sufficient conditions", "tri-gamma functions", "polygamma functions", "trigamma functions", "double inequalities" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0903.3071Q" } } }