Hybrid equation of state approach in binary neutron-star merger simulations

Abstract

We investigate the use of hybrid equations of state in binary neutron-star simulations in full general relativity, where thermal effects are included in an approximate way through the adiabatic index ${\Gamma }_{\mathrm{th}}$. We employ a newly developed finite-temperature equation of state derived in the Brueckner-Hartree-Fock approach and carry out comparisons with the corresponding hybrid versions of the same equation of state, investigating how different choices of ${\Gamma }_{\mathrm{th}}$ affect the gravitational-wave signal and the hydrodynamical properties of the remnant. We also perform comparisons with the widely used SFHo equation of state, detailing the differences between the two cases. Overall, we determine that when using a hybrid equation of state in binary neutron-star simulations, the value of thermal adiabatic index ${\Gamma }_{\mathrm{th}}\approx 1.7$ best approximates the dynamical and thermodynamical behaviour of matter computed using complete, finite-temperature equations of state.

15 pages, 10 figures, accepted for publication in PRD

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Cited by in corpus (7)

• Binary neutron star merger simulations with hot microscopic equations of state
• Microscopic nuclear equation of state at finite temperature and stellar stability
• Hot neutron stars and their equation of state
• Nuclear matter at finite temperature and static properties of proto-neutron star
• Neutron Stars and Gravitational Waves: the Key Role of Nuclear Equation of State
• Thermal effects on nuclear matter properties
• Thermal aspects of neutron star mergers