« Cosmologie/Les perturbations cosmologiques » : différence entre les versions

: <math>\frac{\partial^2 \delta}{\partial^2 t} + 2 H \left( \frac{\partial \delta}{\partial t} \right) = \frac{1}{a^2} \frac{\Delta P}{\rho_m} + \frac{1}{a^2} \times 4 \pi G \rho_m \delta</math>

: <math>\frac{\partial^2 \delta}{\partial^2 t} + 2 H \left( \frac{\partial \delta}{\partial t} \right) = \frac{1}{a^2} \frac{\Delta P}{\rho_m} + \frac{1}{a^2} 4 \pi G \rho_m \delta</math>