Journal
PHYSICAL REVIEW D
Volume 83, Issue 12, Pages -Publisher
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevD.83.123504
Keywords
-
Funding
- PRIN-INAF
- DOE OJI [DE-FG02-95ER40899]
- NSF [AST-0807564]
- NASA [NNX09AC89G]
- World Class University through the National Research Foundation [R32-2009-000-10130-0]
- Ministry of Education, Science and Technology of Korea
- Office of Science, Office of High Energy Physics, of the U.S. Department of Energy [DE-AC02-05CH11231]
Ask authors/readers for more resources
Recent cosmological data analyses hint at the presence of an extra relativistic energy component in the early universe. This component is often parametrized as an excess of the effective neutrino number N-eff over the standard value of 3.046. The excess relativistic energy could be an indication for an extra (sterile) neutrino, but early dark energy and barotropic dark energy also contribute to the relativistic degrees of freedom. We examine the capabilities of current and future data to constrain and discriminate between these explanations, and to detect the early dark energy density associated with them. We find that while early dark energy does not alter the current constraints on N-eff, a dark radiation component, such as that provided by barotropic dark energy models, can substantially change current constraints on N-eff, bringing its value back to agreement with the theoretical prediction. Both dark energy models also have implications for the primordial mass fraction of Helium Y-p and the scalar perturbation index n(s). The ongoing Planck satellite mission will be able to further discriminate between sterile neutrinos and early dark energy.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available