Fermi · Concept Library · Courses · Books · Problems · Simulations · Math Wiki · High School Fermi › Problems General Relativity: An Introduction for Physicists · Problem 15.11
Cosmological models — Hobson, Efstathiou & Lasenby
Physics · conformal-time-field-equation
Problem The conformal time variable is defined by d η = c d t / R d\eta = c\, dt/R d η = c d t / R ( d a d η ) 2 = − k Ω k , 0 ( Ω m , 0 a + Ω r , 0 + Ω Λ , 0 a 4 + Ω k , 0 a 2 ) . \left(\frac{da}{d\eta}\right)^2 = -\frac{k}{\Omega_{k,0}}\left(\Omega_{\mathrm{m},0}\, a + \Omega_{\mathrm{r},0} + \Omega_{\Lambda,0}\, a^4 + \Omega_{k,0}\, a^2\right). ( d η d a ) 2 = − Ω k , 0 k ( Ω m , 0 a + Ω r , 0 + Ω Λ , 0 a 4 + Ω k , 0 a 2 ) . Browse the problem library