Speaker
Description
Neutron stars are fascinating compact objects that provide extreme conditions for studying nuclear matter. By formulating equations of state (EoS) based on assumptions for each region within the star, we can investigate the internal structure of neutron stars. Although much of this research relies on the Tolman–Oppenheimer–Volkoff (TOV) equation—which treats the Einstein field equations under spherical symmetry—observations reveal that neutron stars rotate. Some of them spin at remarkably high rates, known as millisecond pulsars, leading to deformation from perfect sphericity into ellipsoidal shapes. To obtain accurate theoretical predictions, these rotational effects must be incorporated.
Solving the axisymmetric Einstein equations directly cannot be reduced to simple ordinary differential equations, and thus requires numerical methods. One such approach, proposed in 1989 by Komatsu, Eriguchi, and Hachisu and known as the KEH method, transforms these complex differential equations into integral form, enabling stable solutions for the internal structure of rotating neutron stars.
In this study, we employ the Skyrme energy density functional to describe nuclear interactions and apply the KEH method to explore the internal structure of rotating neutron stars. We then discuss how our theoretical predictions compare with observational data and how the resulting constraints on the EoS are influenced by the inclusion of rotation.
