CMB (And Other) Challenges To BBN
Abstract
Primordial nucleosynthesis provides a probe of the universal abundance of baryons when the universe was only a few minutes old. Recent observations of anisotropy in the cosmic microwave background (CMB) probe the baryon abundance when the universe was several hundred thousand years old. Observations of type Ia supernovae and clusters of galaxies in the very recent past, when the universe is several billion years old and older, provide a complementary measure of the baryon density in excellent agreement with the early universe values. The general agreement among the three measurements represents an impressive confirmation of the standard model of cosmology. However, there is a hint that the CMB observations may not be in perfect agreement with those from big bang nucleosynthesis (BBN). If this ``tension" between BBN and the CMB persists, the standard model of cosmology may need to be modified. Here, in a contribution dedicated to Silvia Torres-Peimbert and Manuel Peimbert, we describe how an asymmetry between neutrinos and antineutrinos (``neutrino degeneracy") has the potential for resolving this possible conflict between BBN and the CMB.
- Publication:
-
Revista Mexicana de Astronomia y Astrofisica Conference Series
- Pub Date:
- February 2002
- DOI:
- 10.48550/arXiv.astro-ph/0102152
- arXiv:
- arXiv:astro-ph/0102152
- Bibcode:
- 2002RMxAC..12..265S
- Keywords:
-
- COSMIC MICROWAVE BACKGROUND;
- COSMOLOGICAL PARAMETERS;
- EARLY UNIVERSE;
- Astrophysics
- E-Print:
- Invited talk (G.S.) at the International Symposium on Ionized Gaseous Nebulae to Honour Sylvia Torres-Peimbert &