{ "id": "1506.04925", "version": "v1", "published": "2015-06-16T11:25:53.000Z", "updated": "2015-06-16T11:25:53.000Z", "title": "Dispersion and limit theorems for random walks associated with hypergeometric functions of type BC", "authors": [ "Michael Voit" ], "comment": "Extended version of arXiv:1205.4866", "categories": [ "math.CA", "math-ph", "math.MP", "math.PR", "math.RT" ], "abstract": "The spherical functions of the noncompact Grassmann manifolds $G_{p,q}(\\mathbb F)=G/K$ over the (skew-)fields $\\mathbb F=\\mathbb R, \\mathbb C, \\mathbb H$ with rank $q\\ge1$ and dimension parameter $p>q$ can be described as Heckman-Opdam hypergeometric functions of type BC, where the double coset space $G//K$ is identified with the Weyl chamber $ C_q^B\\subset \\mathbb R^q$ of type B. The corresponding product formulas and Harish-Chandra integral representations were recently written down by M. R\\\"osler and the author in an explicit way such that both formulas can be extended analytically to all real parameters $p\\in[2q-1,\\infty[$, and that associated commutative convolution structures $*_p$ on $C_q^B$ exist. In this paper we introduce moment functions and the dispersion of probability measures on $C_q^B$ depending on $*_p$ and study these functions with the aid of this generalized integral representation. Moreover, we derive strong laws of large numbers and central limit theorems for associated time-homogeneous random walks on $(C_q^B, *_p)$ where the moment functions and the dispersion appear in order to determine drift vectors and covariance matrices of these limit laws explicitely. For integers $p$, all results have interpretations for $G$-invariant random walks on the Grassmannians $G/K$. Besides the BC-cases we also study the spaces $GL(q,\\mathbb F)/U(q,\\mathbb F)$, which are related to Weyl chambers of type A, and for which corresponding results hold. For the rank-one-case $q=1$, the results of this paper are well-known in the context of Jacobi-type hypergroups on $[0,\\infty[$.", "revisions": [ { "version": "v1", "updated": "2015-06-16T11:25:53.000Z" } ], "analyses": { "subjects": [ "33C67", "43A90", "43A62", "60B15", "33C80", "60F05", "60F15" ], "keywords": [ "type bc", "dispersion", "weyl chamber", "moment functions", "invariant random walks" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150604925V" } } }