The Friedmann equations, also known as the Friedmann–Lemaître (FL) equations, are a set of equations in physical cosmology that govern the expansion of...

Friedmann–Lemaître–Robertson–Walker metric (FLRW; /ˈfriːdmən ləˈmɛtrə ... /) is a metric based on an exact solution of the Einstein field equations of...

set of equations he developed known as the Friedmann equations. Alexander Friedmann was born to the composer and ballet dancer Alexander Friedmann (who...

metric, and its time evolution is governed by the Friedmann equations. The second Friedmann equation, a ¨ a = − 4 π G 3 ( ρ + 3 p c 2 ) + Λ c 2 3 , {\displaystyle...

field equations (EFE; also known as Einstein's equations) relate the geometry of spacetime to the distribution of matter within it. The equations were...

lead to the same field equations for General Relativity, i.e., when f ( R ) = R {\displaystyle f(R)=R} , the field equations may differ when f ( R )...

by physicist Alexander Friedmann in 1922 with the mathematical derivation of the Friedmann equations. Independent of Friedmann's work, the Big Bang was...

universe is poised between continued expansion and collapse. From the Friedmann equations, the value for ρ c {\displaystyle \rho _{\text{c}}} critical density...

Bijunath (2008). "Adventures in Friedmann cosmology: A detailed expansion of the cosmological Friedmann equations". American Journal of Physics. 76...

was Alexander Friedmann. Friedmann derived the expanding-universe solution to general relativity field equations in 1922. Friedmann's 1924 papers included...