Tidal deformation and radial pulsations of neutron star with holographic multiquark core

Sitthichai Pinkanjanarod; Piyabut Burikham; Supakchai Ponglertsakul

doi:10.1140/epjc/s10052-022-10106-5

2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2022) 82: 141
https://doi.org/10.1140/epjc/s10052-022-10106-5

Regular Article - Theoretical Physics

Tidal deformation and radial pulsations of neutron star with holographic multiquark core

Sitthichai Pinkanjanarod¹^,2, Piyabut Burikham¹ and Supakchai Ponglertsakul¹^,3

¹ High Energy Physics Theory Group, Department of Physics, Faculty of Science, Chulalongkorn University, 10330, Bangkok, Thailand
² Department of Physics, Faculty of Science, Kasetsart University, 10900, Bangkok, Thailand
³ Department of Physics, Faculty of Science, Silpakorn University, 73000, Nakhon Pathom, Thailand

Received: 28 December 2021
Accepted: 5 February 2022
Published online: 15 February 2022

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, $k_{2}$ $k_{2}$ and $Λ$ $\Lambda$ , are found to be within the physically viable range under the present constraints. Radial pulsation frequencies of the multiquark core for $n = 0 - 5$ $$n=0-5$$ modes are calculated for the entire mass range. For $M_{core} ≃ 2 M_{⊙}$ $M_{\mathrm{core}}\simeq 2 M_{\odot }$ , the fundamental-mode frequency is approximately 2.5 kHz for the energy density scale $ϵ_{s} = 23.2037$ $\epsilon _{s}=23.2037$ GeV/fm $^{3}$ $^{3}$ of the holographic SS model, this frequency is proportional to $\sqrt{ϵ_{s}}$ $\sqrt{\epsilon _{s}}$ .

© The Author(s) 2022

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