Finite temperature effects on the neutrino decoupling in the early Universe

Journal Article · Wed Oct 01 00:00:00 EDT 1997 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.56.5123· OSTI ID:632706

Fornengo, N ^[1]; Kim, C W ^[1]; Song, J ^[1]

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1. Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218 (United States)

Leading finite temperature effects on the neutrino decoupling temperature in the early Universe have been studied. We have incorporated modifications of the dispersion relation and the phase space distribution due to the presence of particles in the heat bath at a temperature of around 1 MeV. Since both the expansion rate of the Universe and the interaction rate of a neutrino are reduced by finite temperature effects, it is necessary to calculate thermal corrections as precisely as possible in order to find the net effect on the neutrino decoupling temperature. We have performed such a calculation by using finite temperature field theory. It has been shown that the finite temperature effects increase the neutrino decoupling temperature by 4.4{percent}, the largest contribution coming from the modification of the phase space due to the thermal bath. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 632706
• Journal Information: Physical Review, D, Vol. 56, Issue 8; Other Information: PBD: Oct 1997
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
NEUTRINOS
DECOUPLING
QUANTUM FIELD THEORY
TEMPERATURE DEPENDENCE
COSMOLOGY
NUCLEOSYNTHESIS
UNIVERSE
DISPERSION RELATIONS
PHASE SPACE
DISTRIBUTION