2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27944Based on a high temperature expansion, we compute the two-point correlation function and the critical line of an Ising lattice gas driven into a non-equilibrium steady state by a uniform bias E. The lowest nontrivial order already reproduces the key features, i.e., the discontinuity singularity of the structure factor and the (qualitative) E-dependence of the critical line. Our approach is easily generalized to other non-equilibrium lattice models and provides a simple analytic tool for the study of the high temperature phase and its boundaries.17 pages, no figures. Some typos corrected. To appear in J. Stat. Phys. (May 1998)Statistical Mechanicstext