f-mode oscillations of dark matter admixed quarkyonic neutron star
D. Dey, Jeet Amrit Pattnaik, M. Bhuyan, R.N. Panda, S. K. Patra
Abstract
Abstract We systematically investigate f -mode oscillations (ℓ = 2) in quarkyonic neutron stars with dark matter, employing the Cowling approximation within the framework of linearized general relativity. The relativistic mean-field approach is used to compute various macroscopic properties of neutron stars. The analysis focuses on three key free parameters in the model: transition density, QCD confinement scale, and dark matter (DM) Fermi momentum, all of which significantly affect the properties of f -mode oscillations. The inclusion of dark matter in quarkyonic equations of state leads to notable variations in f -mode frequencies. Despite these changes, several universal relations among the oscillation properties are found to hold, demonstrating their robustness in the presence of dark matter. Motivation: our model is distinct in that it incorporates quarkyonic matter composed of up and down quarks, which exists in beta equilibrium with neutron star matter, i.e., this model is a combination of the quarkyonic degrees of freedom, the E-RMF framework, and the inclusion of the Fermionic dark matter. To our knowledge, no such unique model exists in the literature. Please note that the development of the model is recently published in JCAP [1], and the present work is an application to f -mode calculations of neutron stars. Understanding the oscillation properties within such a composition provides crucial insights into the possible existence and behavior of quarkyonic matter in neutron stars. This model is a viable alternative to explain the mysterious secondary object present in the recent GW190814 multi-messenger event [2].