Slowly rotating neutron star with holographic multiquark core: I-Love-Q relations

Abstract

Moment of inertia ($I$), rotational (tidal) Love number (${\ensuremath{\lambda}}^{(\mathrm{rot})}$), and quadrupole moment ($Q$) of slowly rotating massive neutron stars (NSs) with holographic multiquarks (MQs) core are computed in comparison to pure MQ stars. The chiral effective theory (CET) stiff equation of state (EoS) is used in the crust of the neutron star. As previously established in earlier work, the dimensionless multipole moments $\overline{I},{\overline{\ensuremath{\lambda}}}^{(\mathrm{rot})}$, and $\overline{Q}$ 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 [Science 341, 365 (2013); Phys. Rev. D 88, 023009 (2013)] are mostly preserved even in the presence of the MQ core. The tidal deformation parameter ${\overline{\ensuremath{\lambda}}}^{(\mathrm{tid})}$ is also explored in connection with $\overline{I},{\overline{\ensuremath{\lambda}}}^{(\mathrm{rot})},\overline{Q}$, and 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 NSs with a MQ core.