Hiding relativistic degrees of freedom in the early universe

V. Barger; James P. Kneller; Paul Langacker; Danny Marfatia; Gary Steigman

doi:10.1016/j.physletb.2003.07.039

Hiding relativistic degrees of freedom in the early universe

V. Barger, James P. Kneller, Paul Langacker, Danny Marfatia, Gary Steigman

Physics

Research output: Contribution to journal › Article › peer-review

86 Scopus citations

Abstract

We quantify the extent to which extra relativistic energy density can be concealed by a neutrino asymmetry without conflicting with the baryon asymmetry measured by the Wilkinson Microwave Anisotropy Probe (WMAP). In the presence of a large electron neutrino asymmetry, slightly more than seven effective neutrinos are allowed by Big Bang Nucleosynthesis (BBN) and WMAP at 2σ. The same electron neutrino degeneracy that reconciles the BBN prediction for the primordial helium abundance with the observationally inferred value also reconciles the LSND neutrino with BBN by suppressing its thermalization prior to BBN.

Original language	English (US)
Pages (from-to)	123-128
Number of pages	6
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	569
Issue number	3-4
DOIs	https://doi.org/10.1016/j.physletb.2003.07.039
State	Published - Sep 11 2003

All Science Journal Classification (ASJC) codes

Nuclear and High Energy Physics

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10.1016/j.physletb.2003.07.039

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title = "Hiding relativistic degrees of freedom in the early universe",

abstract = "We quantify the extent to which extra relativistic energy density can be concealed by a neutrino asymmetry without conflicting with the baryon asymmetry measured by the Wilkinson Microwave Anisotropy Probe (WMAP). In the presence of a large electron neutrino asymmetry, slightly more than seven effective neutrinos are allowed by Big Bang Nucleosynthesis (BBN) and WMAP at 2σ. The same electron neutrino degeneracy that reconciles the BBN prediction for the primordial helium abundance with the observationally inferred value also reconciles the LSND neutrino with BBN by suppressing its thermalization prior to BBN.",

author = "V. Barger and Kneller, {James P.} and Paul Langacker and Danny Marfatia and Gary Steigman",

note = "Funding Information: We thank K. Abazajian, G. Fuller and Y. Wong for enlightening discussions. This research was supported by the US DOE under Grants Nos. DE-FG02-95ER40896, DE-FG02-91ER40676, DE-FG0291ER40690, DE-FG02-02ER41216, and DOE-EY-76-02-3071, by the NSF under Grant No. PHY99-07949, and by the Wisconsin Alumni Research Foundation. V.B., P.L., D.M. and G.S. thank the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara, for its support and hospitality.",

year = "2003",

month = sep,

day = "11",

doi = "10.1016/j.physletb.2003.07.039",

language = "English (US)",

volume = "569",

pages = "123--128",

journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",

issn = "0370-2693",

publisher = "Elsevier B.V.",

number = "3-4",

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TY - JOUR

T1 - Hiding relativistic degrees of freedom in the early universe

AU - Barger, V.

AU - Kneller, James P.

AU - Langacker, Paul

AU - Marfatia, Danny

AU - Steigman, Gary

N1 - Funding Information: We thank K. Abazajian, G. Fuller and Y. Wong for enlightening discussions. This research was supported by the US DOE under Grants Nos. DE-FG02-95ER40896, DE-FG02-91ER40676, DE-FG0291ER40690, DE-FG02-02ER41216, and DOE-EY-76-02-3071, by the NSF under Grant No. PHY99-07949, and by the Wisconsin Alumni Research Foundation. V.B., P.L., D.M. and G.S. thank the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara, for its support and hospitality.

PY - 2003/9/11

Y1 - 2003/9/11

N2 - We quantify the extent to which extra relativistic energy density can be concealed by a neutrino asymmetry without conflicting with the baryon asymmetry measured by the Wilkinson Microwave Anisotropy Probe (WMAP). In the presence of a large electron neutrino asymmetry, slightly more than seven effective neutrinos are allowed by Big Bang Nucleosynthesis (BBN) and WMAP at 2σ. The same electron neutrino degeneracy that reconciles the BBN prediction for the primordial helium abundance with the observationally inferred value also reconciles the LSND neutrino with BBN by suppressing its thermalization prior to BBN.

AB - We quantify the extent to which extra relativistic energy density can be concealed by a neutrino asymmetry without conflicting with the baryon asymmetry measured by the Wilkinson Microwave Anisotropy Probe (WMAP). In the presence of a large electron neutrino asymmetry, slightly more than seven effective neutrinos are allowed by Big Bang Nucleosynthesis (BBN) and WMAP at 2σ. The same electron neutrino degeneracy that reconciles the BBN prediction for the primordial helium abundance with the observationally inferred value also reconciles the LSND neutrino with BBN by suppressing its thermalization prior to BBN.

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U2 - 10.1016/j.physletb.2003.07.039

DO - 10.1016/j.physletb.2003.07.039

M3 - Article

AN - SCOPUS:0041693919

SN - 0370-2693

VL - 569

SP - 123

EP - 128

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

IS - 3-4

ER -

Hiding relativistic degrees of freedom in the early universe

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