Constraining of Nuclear Matter Equations of State With Rotating Neutron Stars

Neutron stars can be regarded as natural laboratories that enable us to investigate nuclear matter properties under extreme conditions that are otherwise impossible to access in terrestrial experiments. Astro­ physical observations of neutron stars provide invaluable information on existing nuclear interaction models and equations of state (EoSs) at various densities. Most studies of neutron star structure employ the Tolman­ Oppenheimer-Volkotf (TOV) equation which describe s spherically symmetric, non-rotating stars in hydrostatic eq uilibrium. However, since neutron stars rotate fast, they could experience significa nt centrifugal deformation, and axially-symmetric calculations are required for accurate description of internal struc ture . The Komatsu­ Eriguchi-Hachisu (KEH) method is well known for modeling rapidly-rotating compact objects in a fully general relativistic manner. In thi s contribution, we report results of KEH calculations for rapidly-rotating neutron stars using EoSs based on Gogny-type finite-range effective nucleon-nucleon interactions. Our results show that the mass-radius relation systema tically changes with increasing angular velocity, highlighting the importance of including rotational effects when confronting theoretical EoSs with observational data.