18. Cosmology I

MIT General Relativity, Spring 2020 Instructor: Scott Hughes View the complete course: YouTube Playlist: Cosmology and cosmological spacetimes.  This is the first spacetime we compute using a symmetry principle.  By requiring that a spacetime be spatially maximally symmetric (i.e., that it have the largest number of possible Killing vectors), we constrain the functional form of its metric.  Imposing the Einstein field equations, we develop a pair of simple equations that control how the overall scale of this spacetime evolves.  The properties of the matter and energy which fill this universe then determine the universe's geometry and how it evolves with time. License: Creative Commons BY-NC-SA More information at More courses at Support OCW at We encourage constructive comments and discussio