{ "id": "math/0603030", "version": "v3", "published": "2006-03-01T19:58:14.000Z", "updated": "2006-03-13T19:01:09.000Z", "title": "On inequalities for sums of bounded random variables", "authors": [ "Iosif Pinelis" ], "comment": "6 pages; the result in the previous version is strengthened and extended", "categories": [ "math.PR", "math.ST", "stat.TH" ], "abstract": "Let $\\eta_{1},\\eta_2,...$ be independent (not necessarily identically distributed) zero-mean random variables (r.v.'s) such that $|\\eta_i|\\le1$ almost surely for all $i$, and let $Z$ stand for a standard normal r.v. Let $a_1,a_2,...$ be any real numbers such that $a_1^2+a_2^2+...=1.$ It is shown that then $$ \\P(a_1\\eta_1+a_2\\eta_2+...\\ge x) \\le \\P(Z\\ge x-\\la/x) \\forall x>0, $$ where $\\la := \\ln\\frac{2e^3}9=1.495...$. The proof relies on (i) another probability inequality and (ii) a l'Hospital-type rule for monotonicity, both developed elsewhere. A multidimensional analogue of this result is given, based on a dimensionality reduction device, also developed elsewhere. In addition, extensions to (super)martingales are indicated.", "revisions": [ { "version": "v3", "updated": "2006-03-13T19:01:09.000Z" } ], "analyses": { "subjects": [ "60E15", "60G50", "60G42", "60G48", "26A48", "26D10" ], "keywords": [ "bounded random variables", "zero-mean random variables", "dimensionality reduction device", "proof relies", "probability inequality" ], "note": { "typesetting": "TeX", "pages": 6, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......3030P" } } }