Friedmann
Friedmann is a surname of German origin. It has been borne by several notable individuals, including the Russian-born physicist and cosmologist Alexander Friedmann, whose work helped establish the expanding-universe model.
Alexander Friedmann (1888–1925) studied solutions to Einstein's field equations that assume a homogeneous and isotropic universe.
Friedmann equations: The two key equations relate the expansion rate to the energy content of the universe,
The standard cosmological model uses the Friedmann-Lemaitre-Robertson-Walker metric, which assumes homogeneity and isotropy. The metric is
In broader usage, Friedmann as a surname appears in various fields, including literature and education, but