Tidal Deformation and Radial Pulsations of Neutron Star with Holographic Multiquark Core

Abstract: Tidal deformation of neutron star with multiquark core is calculated using nuclear and multiquark equations of state. The equation of state of the multiquark phase from the holographic Sakai-Sugimoto~(SS) model is relatively stiff in the low density region and becomes softer at high densities. The values of Love number and dimensionless deformation parameter, $k_{2}$ and $\Lambda$, are found to be within the physically viable range under the present constraints. Radial pulsation frequencies of the multiquark core for $n=0-5$ modes are calculated for the entire mass range. For $M_{\rm core}\simeq 2 M_{\odot}$, the fundamental-mode frequency is approximately $2.5$ kHz for the energy density scale $\epsilon_{s}=23.2037$ GeV/fm$^{3}$ of the holographic SS model, this frequency is proportional to $\sqrt{\epsilon_{s}}$.