Spatially flat FLRW metric

In Cartesian comoving coordinates and signature

(-, +, +, +)

, a spatially flat FLRW universe has

d s^{2} = - c^{2} d t^{2} + a^{2} (t) (d x^{2} + d y^{2} + d z^{2}) .

 Ancestors (5)