ABSTRACT
It has long been a mystery why our universe seems to be so extremely close to the flat case, meaning close to an almost vanishing curvature [182, 183]. The standard cosmological model, mainly based on the Friedmann universe [186, 187], predicts that there should have been either a perfectly flat universe or an extreme increase or a decrease of the parameter of the density ρ since the beginning of time (assumed to be the Big Bang). The equation containing the matter density and comparing it with its critical value guaranteeing a perfectly flat universe ρc in classical cosmology reads: ( ρ c ρ − 1 ) ⋅ ρ ⋅ a [ t ] 2 = c o n s t . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003146445/46b54e56-3535-4028-99ac-a6232858e728/content/math952_B.tif"/>
