Baryon density in alternative big bang nucleosynthesis models
Abstract:We present recent determinations of the cosmological baryon density b, extracted from different kinds of observational data. The baryon density range is not very wide and is usually interpreted as an indication for consistency. All other determinations give higher b values than the standard big bang nucleosynthesis (BBN) model. The differences in the b values from the BBN predicted value (the most precise today) may be due to the statistical and systematic errors in observations. However, they may be an indication of new physics. Hence, it is interesting to study alternative BBN models, and the possibility of resolving these discrepancies. We discuss alternative cosmological scenarios: a BBN model with decaying particles (m of the order of megaelectronvolts; of the order of seconds) and a BBN with electron-sterile neutrino oscillations, which permit us to relax BBN constraints on the baryon content of the Universe.
Document Type: Research Article
Publication date: 2003-08-01