Linearized cosmological continuity equation

For a pressureless fluid with

ρ = \overset{ρ}{ˉ} + ϵ δ ρ, v = ϵ δ v,

the first-order density contrast

δ = δ ρ / \overset{ρ}{ˉ}

obeys

\dot{δ} = - \frac{1}{a} \nabla \cdot δ v .

 Ancestors (6)