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arXiv · 1908.02638

Spin-polarized neutron matter, the maximum mass of neutron stars, and GW170817

I. Tews·A. Schwenk
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Abstract

We investigate how a phase transition from neutron-star matter to spin-polarized neutron matter affects the equation of state and mass-radius relation of neutron stars. While general extension schemes for the equation of state allow for high pressures inside neutron stars, we find that a phase transition to spin-polarized neutron matter excludes extreme regimes. Hence, such a transition limits the maximum mass of neutron stars to lie below 2.6$-$$2.9 \, M_{\odot}$, depending on the microscopic nuclear forces used, while significantly larger masses could be reached without these constraints. These limits are in good agreement with recent constraints extracted from the neutron-star merger GW170817 and its electromagnetic counterpart. Assuming the description in terms of spin-polarized neutron matter to be valid in the center of neutron stars, we find that stars with a large spin-polarized domain in their core are ruled out by GW170817.

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I. Tews, A. Schwenk. 2020-03-24. Spin-polarized neutron matter, the maximum mass of neutron stars, and GW170817. https://doi.org/10.3847/1538-4357%2Fab7232

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