Energy-constrained random walk with boundary replenishment

Wade, Andrew and Grinfeld, Michael (2023) Energy-constrained random walk with boundary replenishment. Journal of Statistical Physics, 190 (10). 155. ISSN 0022-4715 (https://doi.org/10.1007/s10955-023-03165-9)

[thumbnail of Wade-Grinfeld-JSP-2023-Energy-constrained-random-walk-with-boundary-replenishment]
Preview
Text. Filename: Wade_Grinfeld_JSP_2023_Energy_constrained_random_walk_with_boundary_replenishment.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo

Download (638kB)| Preview

Abstract

We study an energy-constrained random walker on a length-N interval of the one-dimensional integer lattice, with boundary reflection. The walker consumes one unit of energy for every step taken in the interior, and energy is replenished up to a capacity of M on each boundary visit. We establish large N, M distributional asymptotics for the lifetime of the walker, i.e., the first time at which the walker runs out of energy while in the interior. Three phases are exhibited. When M≪N2 (energy is scarce), we show that there is an M-scale limit distribution related to a Darling–Mandelbrot law, while when M≫N2 (energy is plentiful) we show that there is an exponential limit distribution on a stretched-exponential scale. In the critical case where M/N2→ρ∈(0, ∞), we show that there is an M-scale limit in terms of an infinitely-divisible distribution expressed via certain theta functions.