Other areas of inquiry Cosmology

Cosmologists also study:

* whether primordial black holes were formed in our universe, and what happened to them.
* the GZK cutoff for high-energy cosmic rays, and whether it signals a failure of special relativity at high energies
* the equivalence principle, and whether Einstein's general theory of relativity is the correct theory of gravitation, and if the fundamental laws of physics are the same everywhere in the universe

Equations of motion

The equations of motion governing the universe as a whole are derived from general relativity with a small, positive cosmological constant. The solution is an expanding universe; due to this expansion the radiation and matter in the universe are cooled down and become diluted. At first the expansion is slowed down by gravitation due to the radiation and matter content of the universe. However, as these become diluted, the cosmological constant becomes more dominant and the expansion of the universe starts to accelerate rather than decelerate. In our universe this has already happened, billions of years ago.