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 $M_{\mathrm{core}}\simeq 2M_{\odot }$, the fundamental-mode frequency is approximately $2.5$ kHz for the energy density scale ${ϵ}_s=23.2037$ GeV/fm${}^3$ of the holographic SS model, this frequency is proportional to $\sqrt{{ϵ}_s}$.

Comments: 9 pages, 5 figures, to appear in EPJC