{ "id": "1510.06451", "version": "v1", "published": "2015-10-21T22:48:13.000Z", "updated": "2015-10-21T22:48:13.000Z", "title": "Thin tails of fixed points of the nonhomogeneous smoothing transform", "authors": [ "Gerold Alsmeyer", "Piotr Dyszewski" ], "comment": "26 pages", "categories": [ "math.PR" ], "abstract": "For a given random sequence $(C,T_{1},T_{2},\\ldots)$ with nonzero $C$ and a.s. finite number of nonzero $T_{k}$, the nonhomogeneous smoothing transform $\\mathcal{S}$ maps the law of a real random variable $X$ to the law of $\\sum_{k\\ge 1}T_{k}X_{k}+C$, where $X_{1},X_{2},\\ldots$ are independent copies of $X$ and also independent of $(C,T_{1},T_{2},\\ldots)$. This law is a fixed point of $\\mathcal{S}$ if the stochastic fixed-point equation (SFPE) $X\\stackrel{d}{=}\\sum_{k\\ge 1}T_{k}X_{k}+C$ holds true, where $\\stackrel{d}{=}$ denotes equality in law. Under suitable conditions including $\\mathbb{E} C=0$, $\\mathcal{S}$ possesses a unique fixed point within the class of centered distributions, called the canonical solution to the above SFPE because it can be obtained as a certain martingale limit in an associated weighted branching model. The present work provides conditions on $(C,T_{1},T_{2},\\ldots)$ such that the canonical solution exhibits right and/or left Poisson tails and the abscissa of convergence of its moment generating function can be determined. As a particular application, the right tail behavior of the Quicksort distribution is found.", "revisions": [ { "version": "v1", "updated": "2015-10-21T22:48:13.000Z" } ], "analyses": { "subjects": [ "60H25", "60E10" ], "keywords": [ "nonhomogeneous smoothing transform", "fixed point", "thin tails", "left poisson tails", "stochastic fixed-point equation" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable" } } }