Temperature dependent appearance of exotic matter makes nascent neutron stars spin faster

Understand

Neutron stars offer the opportunity to study the behaviour of matter at densities and temperatures inaccessible to terrestrial experiments.

• Gravitational-wave observations of binary neutron star coalescences can constrain the neutron-star equation of state before and after merger.
• After the neutron star binary merges, hyperons can form in the remnant, changing the behaviour of the neutron-star equation of state.
• In this study, we use finite-entropy equations of state to show that a post-merger remnant can spin up due to cooling.