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Title: Light sterile neutrinos in the early universe

Abstract

Cosmological and terrestrial data suggests the number of light neutrinos may be greater than 3, motivating a careful reexamination of cosmological bounds on extra light species. Big bang nucleosynthesis constrains the number of relativistic neutrino species present during nucleosynthesis, N{sub eff}{sup BBN}, while measurements of the cosmic microwave background (CMB) angular power spectrum constrain the effective energy density in relativistic neutrinos at the time of matter-radiation equality, N{sub eff}{sup CMB}. We review a scenario with two sterile neutrinos and explore whether partial thermalization of the sterile states can ease the tension between cosmological constraints on N{sub eff}{sup BBN} and terrestrial data. We conclude that, still, two additional light sterile neutrinos species cannot fit all the data at the 95% confidence level.

Authors:
 [1]
  1. Department of Physics, Arizona State University, Tempe, Arizona 85287-1404 (United States)
Publication Date:
OSTI Identifier:
22306114
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 1604; Journal Issue: 1; Conference: PPC 2013: 7. international conference on interconnections between particle physics and cosmology, Lead-Deadwood, SD (United States), 24 Jun - 6 Jul 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ENERGY DENSITY; LIMITING VALUES; NEUTRINOS; NUCLEOSYNTHESIS; RELATIVISTIC RANGE; RELICT RADIATION; REVIEWS; SPECTRA; THERMALIZATION; UNIVERSE

Citation Formats

Lunardini, Cecilia. Light sterile neutrinos in the early universe. United States: N. p., 2014. Web. doi:10.1063/1.4883434.
Lunardini, Cecilia. Light sterile neutrinos in the early universe. United States. https://doi.org/10.1063/1.4883434
Lunardini, Cecilia. 2014. "Light sterile neutrinos in the early universe". United States. https://doi.org/10.1063/1.4883434.
@article{osti_22306114,
title = {Light sterile neutrinos in the early universe},
author = {Lunardini, Cecilia},
abstractNote = {Cosmological and terrestrial data suggests the number of light neutrinos may be greater than 3, motivating a careful reexamination of cosmological bounds on extra light species. Big bang nucleosynthesis constrains the number of relativistic neutrino species present during nucleosynthesis, N{sub eff}{sup BBN}, while measurements of the cosmic microwave background (CMB) angular power spectrum constrain the effective energy density in relativistic neutrinos at the time of matter-radiation equality, N{sub eff}{sup CMB}. We review a scenario with two sterile neutrinos and explore whether partial thermalization of the sterile states can ease the tension between cosmological constraints on N{sub eff}{sup BBN} and terrestrial data. We conclude that, still, two additional light sterile neutrinos species cannot fit all the data at the 95% confidence level.},
doi = {10.1063/1.4883434},
url = {https://www.osti.gov/biblio/22306114}, journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 1604,
place = {United States},
year = {Tue Jun 24 00:00:00 EDT 2014},
month = {Tue Jun 24 00:00:00 EDT 2014}
}