A flexible model for neutron star equation of state from nuclear physics
Development in multi-messenger astronomy over the last few years has
opened new facets to the hadronic matter at densities beyond our terrestrial
reach. It provides new constraints to the theories of nuclear physics, where an
absolute energy density functional is desired from ab-initio mechanisms. Under
the realm of general relativity, there is a one-to-one correspondence between
static observables of a neutron star and the equation of state
(beta-equilibrated). However, high density behaviour of the equation of state is
almost unconstrained in the present scenario. A possible way to explore the
reach of the current theories with nucleonic degrees of freedom was proposed
recently through a meta-modelling, where nuclear matter properties are the
parameters of the density functional. This can be benchmarked as the baseline
to introduce other degrees of freedom (hyperons, deconfined phase) to
investigate the neutron star matter.