Constraints on high density equation of state from maximum neutron star mass

Understand

The low density nuclear matter equation of state is strongly constrained by nuclear properties, however, for constraining the high density equation of state it is necessary to resort to indirect information obtained from the observation of neutron stars, compact objects that may have a central density several times nuclear matter saturation density, $n_0$.

• Taking a meta-modelling approach to generate a huge set of equation of state that satisfy nuclear matter properties close to $n_0$ and that do not contain a first order phase transition, the possibility of constraining the high density equation of state was investigated.
• The entire information obtained from the GW170817 event for the probability distribution of $\tilde{\Lambda}$ was used to make a probabilistic inference of the EOS, which goes beyond the constraints imposed by nuclear matter properties.
• Nuclear matter properties close to saturation, below $2n_0$, do not allow us to distinguish between equations of state that predict different neutron star (NS) maximum masses.