Investigating Signatures of Phase Transitions in Neutron-Star Cores

Rahul Somasundaram (1) , Ingo Tews , Jérôme Margueron (1)

1 IP2I Lyon - Institut de Physique des 2 Infinis de Lyon

Neutron stars explore matter at the highest densities in the universe. In their cores, this matter might undergo a phase transition from hadronic to exotic phases, e.g., quark matter. Such a transition could be indicated by non-trivial structures in the density behavior of the speed of sound such as jumps and sharp peaks. Here, we employ a physics-agnostic approach to model the speed of sound in neutron stars and study to which extent the existence of non-trivial structures can be inferred from existing astrophysical observations of neutron stars. For this, we exhaustively study different equations of state, including those with explicit first-order phase transitions. We conclude that astrophysical information to date do not necessarily require a phase transition to quark matter.

Domains: Nuclear Theory [nucl-th]

Rahul Somasundaram, Ingo Tews, Jérôme Margueron. Investigating Signatures of Phase Transitions in Neutron-Star Cores. Phys.Rev.C, 2023, 107 (2), pp.025801. ⟨10.1103/PhysRevC.107.025801⟩. ⟨hal-03509625⟩