t = 1 H 0 − 1 ∫ 0 1 d x x Ω Λ + Ω k x − 2 + Ω d x − 3 + Ω l x − 4 , x = a a 0 {\displaystyle t={\frac {1}{H_{0}-1}}\int \limits _{0}^{1}{\frac {dx}{x{\sqrt {\Omega _{\Lambda }+\Omega _{k}x^{-2}+\Omega _{d}x^{-3}+\Omega _{l}x^{-4}}}}},x={\frac {a}{a_{0}}}}