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Exotic bulk viscosity and its influence on neutron star r-modes

Debarati Chatterjee·Debades Bandyopadhyay
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Abstract

We investigate the effect of exotic matter in particular, hyperon matter on neutron star properties such as equation of state (EoS), mass-radius relationship and bulk viscosity. Here we construct equations of state within the framework of a relativistic field theoretical model. As hyperons are produced abundantly in dense matter, hyperon-hyperon interaction becomes important and is included in this model. Hyperon-hyperon interaction gives rise to a softer EoS which results in a smaller maximum mass neutron star compared with the case without the interaction. Next we compute the coefficient of bulk viscosity and the corresponding damping time scale due to the non-leptonic weak process including $Λ$ hyperons. Further, we investigate the role of the bulk viscosity on gravitational radiation driven r-mode instability in a neutron star of given mass and temperature and find that the instability is effectively suppressed.

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Debarati Chatterjee, Debades Bandyopadhyay. 2006-12-27. Exotic bulk viscosity and its influence on neutron star r-modes. https://doi.org/10.1007/s10509-007-9356-4

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