{ "id": "1401.8012", "version": "v1", "published": "2014-01-30T22:27:37.000Z", "updated": "2014-01-30T22:27:37.000Z", "title": "Regular variation of infinite series of processes with random coefficients", "authors": [ "Raluca Balan" ], "comment": "19 pages", "categories": [ "math.PR" ], "abstract": "In this article, we consider a series $X(t)=\\sum_{j \\geq 1}\\Psi_j(t) Z_j(t),t \\in [0,1]$ of random processes with sample paths in the space $D=D[0,1]$ of c\\`adl\\`ag functions (i.e. right-continuous functions with left limits) on $[0,1]$. We assume that $(Z_j)_{j \\geq 1}$ are i.i.d. processes with sample paths in $D$ and $(\\Psi_j)_{j \\geq 1}$ are processes with continuous sample paths. Using the notion of regular variation for $D$-valued random elements (introduced in Hult and Lindskog (2005)), we show that $X$ is regularly varying if $Z_1$ is regularly varying, $(\\Psi_j)_{j \\geq 1}$ satisfy some moment conditions, and a certain ``predictability assumption'' holds for the sequence $\\{(Z_j,\\Psi_j)\\}_{j \\geq 1}$. Our result can be viewed as an extension of Theorem 3.1 of Hult and Samorodnitsky (2008) from random vectors in $R^d$ to random elements in $D$. As a preliminary result, we prove a version of Breiman's lemma for $D$-valued random elements, which can be of independent interest.", "revisions": [ { "version": "v1", "updated": "2014-01-30T22:27:37.000Z" } ], "analyses": { "subjects": [ "60G52", "60G17", "62M10" ], "keywords": [ "regular variation", "infinite series", "random coefficients", "valued random elements", "moment conditions" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1401.8012B" } } }