http://arxiv.org/abs/1803.02803
We investigate neutron star tidal deformabilities from cold dense matter equations of state constrained in the low-energy regime (up to twice nuclear saturation density) by chiral effective field theory. We generate over 72,000 energy density functionals fitted simultaneously to the neutron matter equation of state and the properties of symmetric nuclear matter around saturation density. These functionals are then used to compute consistently the neutron star equation of state from the outer crust to the inner core, assuming a composition consisting of protons, neutrons, and electrons. Our results for the neutron star mass-radius relation and dimensionless tidal deformabilities $\Lambda$ are within the range of new constraints deduced from gravitational wave and electromagnetic observations of the GW170817 event. In particular we find that for a 1.4 solar-mass neutron star the tidal deformability lies in the range $350 < \Lambda_{1.4} < 540$. Our predictions for the maximum neutron star mass are largely consistent with new upper bounds predicted from numerical relativity simulations, but we find that lower bounds on the neutron star tidal deformability may be very important for constraining theories of the dense matter equation of state. Finally, we investigate correlations between the density-dependent isospin asymmetry energy and the tidal deformability.
Y. Lim and J. Holt
Tue, 3 Apr 18
28/57
Comments: 7 pages, 6 figures