2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44811The asymptotic form of the energy density for a gas of particles surrounding a sphere of mass $M$ and radius $R$ is studied using Einstein's equations. It is shown that if the pressure of the gas $p$ varies linearly with the energy density $ρ$ for small $ρ$, then $ρ\sim 1/r^2$ for large $r$.PlainTex, 12pagesHigh Energy Physics - PhenomenologyAstrophysicsGeneral Relativity and Quantum Cosmologytext