{ "id": "0906.3037", "version": "v1", "published": "2009-06-16T22:33:12.000Z", "updated": "2009-06-16T22:33:12.000Z", "title": "On the density of the sum of two independent Student t-random vectors", "authors": [ "C. Berg", "C. Vignat" ], "comment": "1 figure", "categories": [ "math.PR" ], "abstract": "In this paper, we find an expression for the density of the sum of two independent $d-$dimensional Student $t-$random vectors $\\mathbf{X}$ and $\\mathbf{Y}$ with arbitrary degrees of freedom. As a byproduct we also obtain an expression for the density of the sum $\\mathbf{N}+\\mathbf{X}$, where $\\mathbf{N}$ is normal and $\\mathbf{X}$ is an independent Student $t-$vector. In both cases the density is given as an infinite series \\[ \\sum_{n=0}^{\\infty} c_{n}f_{n} \\] where $f_{n}$ is a sequence of probability densities on $\\mathbb{R}^{d}$ and $(c_{n} )$ is a sequence of positive numbers of sum 1, i.e. the distribution of a non-negative integer-valued random variable $C$, which turns out to be infinitely divisible for $d=1$ and $d=2.$ When $d=1$ and the degrees of freedom of the Student variables are equal, we recover an old result of Ruben.", "revisions": [ { "version": "v1", "updated": "2009-06-16T22:33:12.000Z" } ], "analyses": { "subjects": [ "60E05" ], "keywords": [ "independent student t-random vectors", "old result", "arbitrary degrees", "expression", "dimensional student" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0906.3037B" } } }