2007
Author(s): Popa, LA (Popa, L. A.); Vasile, A (Vasile, A.)
Edited by: Trache L; Stoica S
Source: EXOTIC NUCLEI AND NUCLEAR /PARTICLE ASTROPHYSICS (II) Book Series: AIP Conference Proceedings Volume: 972 Pages: 521-525 Published Date: 2008
Abstract: By using most of the present Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) measurements we set bounds on the radiation content of the Universe and neutrino properties. We consider lepton asymmetric cosmological models parametrized by the neutrino degeneracy parameter xi(nu) and the variation of the relativistic degrees of freedom, Delta N-eff(oth), due to possible unknown physical processes during BBN.
We found 0 < xi(nu) < 0.788 (2 sigma) that implies a lepton asymmetry of the neutrino background 0.001 < L-nu < 0.661. We also found 0.079 Delta N-eff(oth) < 2.555 (2 sigma) and the contribution to the total number of relativistic degrees of freedom - 1.107 < Delta N-eff < 3.482.
These results bring an important improvement over the same parameters obtained by using the WMAP data alone, showing that the LSS measurements are useful tools in constraining the radiation content of the Universe during BBN.
Accession Number: WOS:000253372300064
Conference Title: 22nd Carpathian Summer School of Physics 2007
Conference Date: AUG 20-31, 2007
Conference Location: Sinaia, ROMANIA
Conference Sponsors: Natl Inst Phys & Nuclear Engn, Cyclotron Inst, Texas A&M Univ, Coll Stn, Romanian Natl Author Sci Res