2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/190330We study the cosmology of models with four space and one time dimension where our universe is a 3-brane and report a few results which extend existing work in several directions. Assuming a stable fifth dimension, we obtain a solution for the metric, which does not depend on any arbitrary parameters. We discuss some implications of this result.Minor changes: brane energy conservation law and some typos corrected. All main results unchanged. 11 pages, no figures, LaTeX fileHigh Energy Physics - PhenomenologyAstrophysicsHigh Energy Physics - Theorytext