Probing the Effective Number of Neutrino Species with Cosmic Microwave Background
| dc.creator | Ichikawa, Kazuhide | |
| dc.creator | Sekiguchi, Toyokazu | |
| dc.creator | Takahashi, Tomo | |
| dc.date | 2008-03-06 | |
| dc.date | 2008-10-21 | |
| dc.date.accessioned | 2026-07-07T11:48:56Z | |
| dc.date.available | 2026-07-07T11:48:56Z | |
| dc.description | We discuss how much we can probe the effective number of neutrino species N_nu with cosmic microwave background alone. Using the data of WMAP, ACBAR, CBI and BOOMERANG experiments, we obtain a constraint on the effective number of neutrino species as 0.96< N_nu <7.94 at 95% C.L. for a power-law LCDM flat universe model. The limit is improved to be 1.39 < N_nu < 6.38 at 95% C.L. if we assume that the baryon density, N_nu and the helium abundance are related by the big bang nucleosynthesis theory. We also provide a forecast for the PLANCK experiment using a Markov chain Monte Carlo approach. In addition to constraining N_nu, we investigate how the big bang nucleosynthesis relation affects the estimation for these parameters and other cosmological parameters. | |
| dc.description | 19 pages, 4 figures, 4 tables; update after WMAP 5-year results; accepted for publication in Phys. Rev. D | |
| dc.identifier | https://arxiv.org/abs/0803.0889 | |
| dc.identifier | http://arxiv.org/abs/0803.0889 | |
| dc.identifier | Phys.Rev.D78:083526,2008 | |
| dc.identifier | doi:10.1103/PhysRevD.78.083526 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/203060 | |
| dc.subject | Astrophysics | |
| dc.title | Probing the Effective Number of Neutrino Species with Cosmic Microwave Background | |
| dc.type | text |