Slowly Rotating Neutron Star with Holographic Multiquark Core: I-Love-Q Relations

Abstract

Moment of inertia ($I$), rotational~(tidal) Love number ($\lambda^{\rm (rot)}$) and quadrupole moment ($Q$) of slowly rotating massive neutron star~(NS) with holographic multiquark~(MQ) core are computed in comparison to pure MQ star. The Chiral Effective Theory~(CET) stiff equation of state~(EoS) is used in the crust of the neutron star. The dimensionless multipole moments $\bar{I},\bar{\lambda}^{\rm (rot)}, \bar{Q}$ are found to be independent of the rotation parameters and determined completely by the zeroth-order star profile. Universal ``I-Love-Q'' relations found by Yagi and Yunes [1,2] are mostly preserved even in the presence of the MQ core. Tidal deformation parameter $\bar{\lambda}^{\rm (tid)}$ is also explored in connection with $\bar{I}, \bar{\lambda}^{\rm (rot)}, \bar{Q}$, two kinds of universal I-Love-Q relations are verified. However, the unique kink in the plots of multipoles with respect to mass and compactness of the population of neutron stars can reveal the existence of massive NS with the MQ core.