GW170817: Constraining the nuclear matter equation of state from the neutron star tidal deformability

Abstract

Constraints set on key parameters of the nuclear matter equation of state (EoS) by the values of the tidal deformability, inferred from GW170817, are examined by using a diverse set of relativistic and non-relativistic mean field models. These models are consistent with bulk properties of finite nuclei as well as with the observed lower bound on the maximum mass of neutron star ∼ 2 M⊙. The tidal deformability shows a strong correlation with specific linear combinations of the isoscalar and isovector nuclear matter parameters associated with the EoS. Such correlations suggest that a precise value of the tidal deformability can put tight bounds on several EoS parameters, in particular, on the slope of the incompressibility and the curvature of the symmetry energy. The tidal deformability obtained from the GW170817 and its UV/optical/infrared counterpart sets the radius of a canonical 1.4 M⊙ neutron star to be 11.82 R1.4 13.72 km.

Magnetized hybrid stars: effects of slow and rapid phase transitions at the quark–hadron interface

“…Last but not least, the recent new constrains arising from the gravitational wave detections were considered. In the M-R plane, we verified that the R 1.4 13.76 km condition (Raithel et al 2018;Annala et al 2018;Malik et al 2018;Most et al 2018;Fattoyev et al 2018) is satisfied together with the restriction ofΛ < 800 (Abbott et al 2017a) in the Λ-M plane.…”

“…The upper limit on the tidal deformability of the binary system,Λ < 800 (Abbott et al 2017a), has restricted the radius of a NS with a mass of 1.4 M to R 1. 4 13.76 km (Raithel et al 2018;Annala et al 2018;Malik et al 2018;Most et al 2018;Fattoyev et al 2018). In summary, although the EoS of extremely dense matter is still uncertain, new multi-messenger observations provide tight constraints for current models.…”

Role of the symmetry energy and the neutron-matter stiffness on the tidal deformability of a neutron star with unified equations of state

“…[34]. Malik et al [13] have recently examined possible correlations between tidal deformabilities and nuclear-matter parameters for a large set of EoSs. As can be seen from their results in Table I for a few selected NS masses, the symmetry-energy coefficient J (denoted by J 0 in their paper) has essentially no impact on k 2 and the slope L of the symmetry energy at saturation (denoted by L 0 in their paper) has only a moderate influence on k 2 (a similar conclusion can be drawn from the recent analysis of Ref.…”

“…EoS at densities relevant for medium-mass NSs. Incidentally, the analyses of K + production[95][96][97] and π − /π + production ratio[98] in heavy-ion collisions provide evidence for a soft EoS at similar densities.Combining empirical relations between Λ 1.4 and R 1.4 (see Section III B 1) with the upper limits on the tidal deformability obtained from the analyses of the gravitational-wave signal by the LIGO-Virgo collaboration[1,11] and De et al[10], different constraints have been proposed for the radius of a 1.4 M NS (see, e.g., Refs [13,14,17,77,99,100]…”

Empirical constraints on the high-density equation of state from multimessenger observables

“…Correlations between nuclear matter parameters and NS properties have been explored using several nuclear models [24][25][26][27][28][29][30][31][32]. These studies, however, show a considerable model dependence since different models with similar values of the nuclear matter parameters may result in different EoSs.…”