2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/161662We discuss the question of recurrence for persistent, or Newtonian, random walks in Z^2, i.e., random walks whose transition probabilities depend both on the walker's position and incoming direction. We use results by Toth and Schmidt-Conze to prove recurrence for a large class of such processes, including all "invertible" walks in elliptic random environments. Furthermore, rewriting our Newtonian walks as ordinary random walks in a suitable graph, we gain a better idea of the geometric features of the problem, and obtain further examples of recurrence.20 pages, 7 figuresProbabilityMathematical Physics60G50, 37B20, 60K37, 82C41text