Bulk viscosity of baryonic matter with trapped neutrinos
| Autor: | Arus Harutyunyan, Mark G. Alford, Armen Sedrakian |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Nuclear Theory
Astrophysics::High Energy Astrophysical Phenomena media_common.quotation_subject FOS: Physical sciences 01 natural sciences Asymmetry Nuclear Theory (nucl-th) 0103 physical sciences 010306 general physics Solar and Stellar Astrophysics (astro-ph.SR) media_common High Energy Astrophysical Phenomena (astro-ph.HE) Physics Condensed matter physics 010308 nuclear & particles physics High Energy Physics::Phenomenology Volume viscosity Nuclear matter Baryon Neutron star Astrophysics - Solar and Stellar Astrophysics Isospin High Energy Physics::Experiment Neutrino Astrophysics - High Energy Astrophysical Phenomena Lepton |
| Zdroj: | Physical Review D. 100 |
| ISSN: | 2470-0029 2470-0010 |
| Popis: | We study bulk viscosity arising from weak current Urca processes in dense baryonic matter at and beyond nuclear saturation density. We consider the temperature regime where neutrinos are trapped and therefore have nonzero chemical potential. We model the nuclear matter in a relativistic density functional approach, taking into account the trapped neutrino component. We find that the resonant maximum of the bulk viscosity would occur at or below the neutrino trapping temperature, so in the neutrino trapped regime the bulk viscosity decreases with temperature as $T^{-2}$, this decrease being interrupted by a drop to zero at a special temperature where the proton fraction becomes density-independent and the material scale-invariant. The bulk viscosity is larger for matter with lower lepton fraction, i.e., larger isospin asymmetry. We find that bulk viscosity in the neutrino-trapped regime is smaller by several orders of magnitude than in the neutrino-transparent regime, which implies that bulk viscosity in neutrino-trapped matter is probably not strong enough to affect significantly the evolution of neutron star mergers. This also implies weak damping of gravitational waves emitted by the oscillations of the postmerger remnant in the high-temperature, neutrino-trapped phase of evolution. Comment: v2: matches published version, 27 pages, 21 figures, uses RevTex |
| Databáze: | OpenAIRE |
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