{ "id": "1205.1284", "version": "v1", "published": "2012-05-07T05:13:40.000Z", "updated": "2012-05-07T05:13:40.000Z", "title": "An Inequality Related to Negative Definite Functions", "authors": [ "M. Lifshits", "R. L. Schilling", "I. Tyurin" ], "categories": [ "math.PR" ], "abstract": "This is a substantially generalized version of the preprint arXiv:1105.4214 by Lifshits and Tyurin. We prove that for any pair of i.i.d. random vectors $X, Y$ in $R^n$ and any real-valued continuous negative definite function $g: R^n\\to R$ the inequality $$ E g(X-Y) \\le E g(X+Y)$$ holds. In particular, for $a \\in (0,2]$ and the Euclidean norm $|.|$ one has $$ E |X-Y|^a \\le E |X+Y|^a. $$ The latter inequality is due to A. Buja et al. (Ann. Statist., 1994} where it is used for some applications in multivariate statistics. We show a surprising connection with bifractional Brownian motion and provide some related counter-examples.", "revisions": [ { "version": "v1", "updated": "2012-05-07T05:13:40.000Z" } ], "analyses": { "subjects": [ "60E15", "60G22", "60E10" ], "keywords": [ "inequality", "bifractional brownian motion", "euclidean norm", "random vectors", "real-valued continuous negative definite function" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1205.1284L" } } }