TY - JOUR
T1 - Fugacity and reheating of primordial neutrinos
AU - Birrell, Jeremiah
AU - Yang, Cheng Tao
AU - Chen, Pisin
AU - Rafelski, Johann
N1 - Funding Information:
J.R. is supported by a grant from the U.S. Department of Energy, DE-FG02-04ER41318. J.B. is supported by the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program. C.T.Y. and P.C. are supported by Taiwan National Science Council under Project Nos. NSC 101-2923-M-002-006-MY3 and 101-2628-M-002-006-and by Taiwan’s National Center for Theoretical Sciences (NCTS). P.C. is in addition supported by US Department of Energy under Contract No. DE-AC03-76SF00515.
PY - 2013/12/28
Y1 - 2013/12/28
N2 - We clarify in a quantitative way the impact that distinct chemical T c and kinetic Tk freeze-out temperatures have on the reduction of the neutrino fugacity Υν below equilibrium, i.e. Υν<1, and the increase of the neutrino temperature T ν via partial reheating. We establish the connection between Υν and Tk via the modified reheating relation Tν(Υν)/Tγ, where T γ is the temperature of the background radiation. Our results demonstrate that one must introduce the chemical nonequilibrium parameter, i.e. the fugacity, Υν, as an additional standard cosmological model parameter in the evaluation of CMB fluctuations as its value allows measurement of Tk.
AB - We clarify in a quantitative way the impact that distinct chemical T c and kinetic Tk freeze-out temperatures have on the reduction of the neutrino fugacity Υν below equilibrium, i.e. Υν<1, and the increase of the neutrino temperature T ν via partial reheating. We establish the connection between Υν and Tk via the modified reheating relation Tν(Υν)/Tγ, where T γ is the temperature of the background radiation. Our results demonstrate that one must introduce the chemical nonequilibrium parameter, i.e. the fugacity, Υν, as an additional standard cosmological model parameter in the evaluation of CMB fluctuations as its value allows measurement of Tk.
KW - Big bang nucleosynthesis
KW - Elementary particle processes
KW - Kinetic and transport theory of gases
KW - Neutrino mass and mixing
UR - http://www.scopus.com/inward/record.url?scp=84890390564&partnerID=8YFLogxK
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U2 - 10.1142/S0217732313501885
DO - 10.1142/S0217732313501885
M3 - Article
AN - SCOPUS:84890390564
SN - 0217-7323
VL - 28
JO - Modern Physics Letters A
JF - Modern Physics Letters A
IS - 40
M1 - 1350188
ER -