微中子的逸散度對早期微中子及宇宙演化之影響

Impact of the Neutrino Fugacity in the Early Universe

陳鈞彥(Chun-Yen Chen)

指導教授 ： 陳丕燊

國立臺灣大學/理學院/物理學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201602566

摘要

無資料

關鍵字

微中子 ； 逸散度 ； 早期宇宙 ； 宇宙背景輻射 ； 大霹靂核合成

並列摘要

Neutrinos are important for the evolution of early universe. The abundance
of neutrinos will affect the expansion rate of universe and so that affect the
Big Bang nucleosynthesis and cosmic microwave background. In this paper,
the consequences of a nonzero neutrino fugacity in the early universe are
considered. In contrast to the standard chemical potential, which controls
the asymmetry between the number density of neutrinos and anti-neutrinos,
fugacity determines the total number density of neutrinos and anti-neutrinos,
which is essential in describing the neutron evolution in the early universe.
I will introduce the physics about the early universe and some physics
about neutrino first. Then an approximate solution to the neutrino Lepton
asymmetry is derived from the neutrino quantum kinetic equations and used
to study the influence of neutrino fugacity. Also the numerical result will
be shown in this paper. In the end, the impact of neutrino’s fugacity on Big
Bang Nucleosynthesis (BBN) and Cosmic Microwave Background (CMB)
via effective number Neff of neutrinos will be discussed.

並列關鍵字

neutrino ； fugacity ； early universe ； quantum kinetic equation ； effective number ； Big Bang Nucleosynthesis ； Cosmic Microwave Background

參考文獻

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[4] Friedmann, A (1999). On the Curvature of Space. General Relativity and Gravitation 31 (12): 1991 – 2000.

[5] P.W. Higgs, Broken Symmetries and the Masses of Gauge Bosons, Phys. Rev. Lett. 12, 132 (1964)