Final answer:
The assumptions that go into the Friedmann equation include the homogeneity and isotropy of the universe, the absence of external forces, and the principles of general relativity.
Step-by-step explanation:
The assumptions that go into the Friedmann equation include:
- The universe is homogeneous and isotropic on large scales
- The universe can be described by expanding or contracting space, without any external forces or sources
- The universe follows the principles of general relativity
These assumptions help in simplifying the equations and describing the overall behavior of the universe. The Friedmann equation is a fundamental equation of cosmology that relates the expansion rate of the universe to its energy content.