{ "id": "1402.4147", "version": "v1", "published": "2014-02-17T21:12:41.000Z", "updated": "2014-02-17T21:12:41.000Z", "title": "Fixed points of multivariate smoothing transforms with scalar weights", "authors": [ "Alexander Iksanov", "Matthias Meiners" ], "comment": "43 pages", "categories": [ "math.PR" ], "abstract": "Given a sequence $(C_1,\\ldots,C_d,T_1,T_2,\\ldots)$ of real-valued random variables with $N := \\#\\{j \\geq 1: T_j \\not = 0\\} < \\infty$ almost surely, there is an associated smoothing transformation which maps a distribution $P$ on $\\mathbb{R}^d$ to the distribution of $\\sum_{j \\geq 1} T_j \\mathbf{X}^{(j)} + \\mathbf{C}$ where $\\mathbf{C} = (C_1,\\ldots,C_d)$ and $(\\mathbf{X}^{(j)})_{j \\geq 1}$ is a sequence of independent random vectors with distribution $P$ independent of $(C_1,\\ldots,C_d,T_1,T_2,\\ldots)$. We are interested in the fixed points of this mapping. By improving on the techniques developed in [G. Alsmeyer, J.D. Biggins, and M. Meiners. The functional equation of the smoothing transform {\\em Ann. Probab.}, 40(5):2069--2105, 2012] and [G. Alsmeyer and M. Meiners. Fixed points of the smoothing transform: two-sided solutions. {\\em Probab. Theory Related Fields}, 155(1-2):165--199, 2013], we determine the set of all fixed points under weak assumptions on $(C_1,\\ldots,C_d,T_1,T_2,\\ldots)$. In contrast to earlier studies, this includes the most intricate case when the $T_j$ take both positive and negative values with positive probability. In this case, in some situations, the set of fixed points is a subset of the corresponding set when the $T_j$ are replaced by their absolute values, while in other situations, additional solutions arise.", "revisions": [ { "version": "v1", "updated": "2014-02-17T21:12:41.000Z" } ], "analyses": { "subjects": [ "60J80", "39B32" ], "keywords": [ "fixed points", "multivariate smoothing transforms", "scalar weights", "distribution", "independent random vectors" ], "note": { "typesetting": "TeX", "pages": 43, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1402.4147I" } } }