Physics – Nuclear Physics
Scientific paper
Oct 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998aps..dnp..a101t&link_type=abstract
American Physical Society, Division of Nuclear Physics Meeting, October 28-31, 1998 Santa Fe, New Mexico, abstract #A1.01
Physics
Nuclear Physics
Scientific paper
Big-bang nucleosynthesis (BBN) is one of the cornerstones of the standard hot big-bang cosmology. It provides the earliest test of the standard cosmology -- back to temperatures of \cal O(10 MeV) -- and thereby opens the door to the study of the very early Universe, from which so many of the seminal ideas in cosmology today have emerged (e.g., particle dark matter and inflation). In addition to its role as a test of the big-bang cosmology, it provides the best determination of the density of ordinary matter and a very stringent limit to the number of particle species lighter than about 1 MeV. Based upon the recently measured primeval abundance of deuterium, BBN implies that ΩB = (0.02± 0.002)h-2 ~= 0.05 (for h=2/3). BBN is the linchpin in the case for nonbaryonic dark matter as Ω_B(BBN) << Ω_matter = 0.35± 0.07. The BBN limit to the number of light particle species, expressed as an equivalent number of neutrino species, is N_ν < 3.4 (95%); it is a powerful constraint to unified models of the elementary particles. The predictions of BBN are robust because the cross sections for the key reactions are measured at the energies of relevance for the early Universe; indeed, the most precise BBN predictions come from a recent study where the data themselves are used as the nuclear-physics input. A growing body of high-precision data is ushering in a precision era in cosmology; to take full advantage of this requires theoretical predictions of increasing accuracy. For BBN, this requires better measurements of the reactions ^3He(α ,γ)^7Be, d(p,γ)^3He, d(d,n)^3He, ^3He(d,p)^4He, and ^7Be(n,p)^7Li, as well as a better theoretical calculation of p(n,γ)d. The potential rewards are great: a 5% or better determination of the baryon density, which, when compared to the expected measurement of similar accuracy from CBR anisotropy, will be a new consistency test of the big bang, and a more stringent limit to the number of light particle species, perhaps as stringent as N_ν < 3.05.
No associations
LandOfFree
Big-bang Nucleosynthesis in the Era of Precision Cosmology does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Big-bang Nucleosynthesis in the Era of Precision Cosmology, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Big-bang Nucleosynthesis in the Era of Precision Cosmology will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1720820