Big Bang Nucleosynthesis, in spite of its uncertainties, still gives a robust upper bound on Ωbaryon, as I describe. However, when this bound is compared with a lower bound on Ωbaryon as derived from observations of X-Ray clusters, a REAL baryon crisis emerges, which suggests that either the universe is open, or there is a cosmological constant. When combined with other cosmological data, the case for a cosmological constant is strengthened.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics