The De sitter solution models the universe as spatially flat, neglecting ordinary matter, such that it is dominated by the cosmological constant. The cosmological constant notion arguably suggests the existence of dark energy, but exactly how accurate is the model? Can we mathematically prove its accuracy?

  • $\begingroup$ Applies to our universe? Our universe is certainly not de Sitter, if it were then cosmology books would be a lot shorter. But it is a useful approximation at some times. $\endgroup$
    – knzhou
    Apr 15, 2019 at 0:02
  • $\begingroup$ I'd suggest that this answer to the related question What is the geometry of the Universe ought to be your first port of call. I would, however, say you cannot prove a physical theory is accurate (i.e. matches reality) by mathematics alone. $\endgroup$ Apr 15, 2019 at 2:22
  • $\begingroup$ I'm not sure what you're asking. Anyway, our universe could not be exactly de Sitter. This is because we (and earth, planets, large scale structure..), aka inhomogeneities, exist $\endgroup$
    – Avantgarde
    Apr 15, 2019 at 22:03


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.