{ "id": "1503.00871", "version": "v1", "published": "2015-03-03T09:56:25.000Z", "updated": "2015-03-03T09:56:25.000Z", "title": "Linear forms of the telegraph random processes driven by partial differential equations", "authors": [ "Alexander D. Kolesnik" ], "comment": "23 pages", "categories": [ "math.PR" ], "abstract": "Consider $n$ independent Goldstein-Kac telegraph processes $X_1(t), \\dots ,X_n(t), \\; n\\ge 2, \\; t\\ge 0,$ on the real line $\\Bbb R$. Each the process $X_k(t), \\; k=1,\\dots,n,$ describes a stochastic motion at constant finite speed $c_k>0$ of a particle that, at the initial time instant $t=0$, starts from some initial point $x_k^0=X_k(0)\\in\\Bbb R$ and whose evolution is controlled by a homogeneous Poisson process $N_k(t)$ of rate $\\lambda_k>0$. The governing Poisson processes $N_k(t), \\; k=1,\\dots,n,$ are supposed to be independent as well. Consider the linear form of the processes $X_1(t), \\dots ,X_n(t), \\; n\\ge 2,$ defined by $$L(t) = \\sum_{k=1}^n a_k X_k(t) ,$$ where $a_k, \\; k=1,\\dots,n,$ are arbitrary real non-zero constant coefficients. We obtain a hyperbolic system of first-order partial differential equations for the joint probability densities of the process $L(t)$ and of the directions of motions at arbitrary time $t>0$. From this system we derive a partial differential equation of order $2^n$ for the transition density of $L(t)$ in the form of a determinant of a block matrix whose elements are the differential operators with constant coefficients. The weak convergence of $L(t)$ to a homogeneous Wiener process, under Kac's scaling conditions, is proved. Initial-value problems for the transition densities of the sum and difference $S^{\\pm}(t)=X_1(t) \\pm X_2(t)$ of two independent telegraph processes with arbitrary parameters, are also posed.", "revisions": [ { "version": "v1", "updated": "2015-03-03T09:56:25.000Z" } ], "analyses": { "subjects": [ "60G50", "60J60", "35G10", "35G05", "35L55", "60E10" ], "keywords": [ "partial differential equation", "telegraph random processes driven", "linear form", "arbitrary real non-zero constant coefficients" ], "note": { "typesetting": "TeX", "pages": 23, "language": "en", "license": "arXiv", "status": "editable" } } }