 formula_6

Here, formula_7 is the total radiation energy density, formula_8 is the total matter density, formula_9 is the dark energy density, formula_10 represents the curvature, formula_11 is the Hubble parameter today and formula_12 is the speed of light.The Hubble parameter at a given redshift is then formula_13.To compute the distance to an object from its redshift, we must integrate the above equation.