On the Markov transition kernels for first passage percolation on the ladder

Abstract

We consider the first passage percolation problem on the random graph with vertex set N x {0, 1}, edges joining vertices at a Euclidean distance equal to unity, and independent exponential edge weights. We provide a central limit theorem for the first passage times l_n between the vertices (0, 0) and (n, 0), thus extending earlier results about the almost-sure convergence of l_n / n as n → ∞. We use generating function techniques to compute the n-step transition kernels of a closely related Markov chain which can be used to explicitly calculate the asymptotic variance in the central limit theorem.