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Bulk viscosity of a gas of neutrinos and coupled scalar particles, in the era of recombination

R. F. Sawyer
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Abstract

Bulk viscosity may serve to damp sound waves in a system of neutrinos coupled to very light scalar particles, in the era after normal neutrino decoupling but before recombination. We calculate the bulk viscosity parameter in a minimal scheme involving the coupling of the two systems. We add some remarks on the bulk viscosity of a system of fully ionized hydrogen plus photons.

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R. F. Sawyer. 2006-01-23. Bulk viscosity of a gas of neutrinos and coupled scalar particles, in the era of recombination. https://doi.org/10.1103/physrevd.74.043527

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