{ "id": "0806.3188", "version": "v1", "published": "2008-06-19T13:45:00.000Z", "updated": "2008-06-19T13:45:00.000Z", "title": "Existence of a critical point for the infinite divisibility of squares of Gaussian vectors in $R^{2}$ with non--zero mean", "authors": [ "Michael B. Marcus", "Jay Rosen" ], "categories": [ "math.PR" ], "abstract": "Let $G=(G_{1},G_{2})$ be a Gaussian vector in $R^{2}$ with $EG_{1}G_{2}\\neq 0$. Let $c_{1},c_{2}\\in R^{1}$. A necessary and sufficient condition for $G=((G_{1}+c_{1}\\alpha)^{2},(G_{2}+c_{2}\\alpha)^{2})$ to be infinitely divisible for all $\\alpha\\in R^{1}$ is that \\[ \\Ga_{i,i}\\geq \\frac{c_{i}}{c_{j}}\\Ga_{i,j}>0\\qquad\\forall 1\\le i\\ne j\\le 2.\\] In this paper we show that when this does not hold there exists an $0<\\alpha_{0}<\\ff $ such that $G=((G_{1}+c_{1}\\alpha)^{2},(G_{2}+c_{2}\\alpha)^{2})$ is infinitely divisible for all $|\\alpha|\\leq \\alpha_{0}$ but not for any $|\\al|>\\al_{0}$.", "revisions": [ { "version": "v1", "updated": "2008-06-19T13:45:00.000Z" } ], "analyses": { "subjects": [ "60G15", "60E07" ], "keywords": [ "gaussian vector", "non-zero mean", "infinite divisibility", "critical point", "sufficient condition" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2008arXiv0806.3188M" } } }