2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/191470Using big bang nucleosynthesis and present, high-precision measurements of light element abundances, we constrain the self-gravity of radiation pressure in the early universe. The self-gravity of pressure is strictly non-Newtonian, and thus the constraints we set provide a direct test of this prediction of general relativity and of the standard, Robertson-Walker-Friedmann cosmology.5 pages, 1 figure. This paper was developed from an earlier version which was posted as arXiv:0707.3589Astrophysicstext