Noun
English Wikipedia has an article on:Cosmological PrincipleWikipedia
cosmological principle
(astronomy) The assumption that the universe, on a large enough scale, is homogeneous and isotropic.
Peacock (1999), chapter 3 That space is undergoing metric expansion is shown by direct observational evidence of the Cosmological principle and the Copernican principle, which together with Hubble's law have no other explanation. Source: Internet
Modern mathematical cosmology is based on the assumption that the Cosmological principle is almost, but not exactly, true on the largest scales. Source: Internet