Open quantum random walks on the half-line: the Karlin-McGregor formula, path counting and Foster's Theorem
Abstract
In this work we consider open quantum random walks on the non-negative integers. By considering orthogonal matrix polynomials we are able to describe transition probability expressions for classes of walks via a matrix version of the Karlin-McGregor formula. We focus on absorbing boundary conditions and, for simpler classes of examples, we consider path counting and the corresponding combinatorial tools. A non-commutative version of the gambler's ruin is studied by obtaining the probability of reaching a certain fortune and the mean time to reach a fortune or ruin in terms of generating functions. In the case of the Hadamard coin, a counting technique for boundary restricted paths in a lattice is also presented. We discuss an open quantum version of Foster's Theorem for the expected return time together with applications.
Keywords
Cite
@article{arxiv.1701.08400,
title = {Open quantum random walks on the half-line: the Karlin-McGregor formula, path counting and Foster's Theorem},
author = {Thomas S. Jacq and Carlos F. Lardizabal},
journal= {arXiv preprint arXiv:1701.08400},
year = {2017}
}
Comments
Revised version, includes a general version of the gambler's ruin problem and other applications to Foster's Theorem