Implications of Fermionic Dark Matter Interactions on Anisotropic Neutron Stars

Abstract

The presence of Dark matter (DM) within a neutron star (NS) can substantially influence the macroscopic properties. It is commonly assumed that the pressure inside an NS is isotropic, but in reality, pressure is locally anisotropic. This study explores the properties of anisotropic NS with a subfraction of DM (isotropic) trapped inside. Implementing a two-fluid formalism with three Equations of State (EOS): AP3 (a realistic nucleon-nucleon interaction model), BSk22 (modeling atomic nuclei and neutron-matter), and MPA1 (considering relativistic effects in nuclear interactions). The properties of NS, such as mass ($M$), radius ($R$), and dimensionless tidal deformability ($\Lambda$), for various DM-anisotropic configurations, have been rigorously tested against observational constraints. These constraints include data from the binary NS merger GW170817, NICER x-ray measurements, and pulsar mass-radius observations. We observe that with increasing DM subfraction, higher anisotropies could also satisfy the observational constraints. Furthermore, increasing the coupling ($g$) between DM and its mediator leads to the formation of a core-halo structure, with a DM halo surrounding the baryonic matter (BM). Specifically, for coupling values of $g=10^{-4}$, $10^{-3.7}$, and $10^{-3.5}$, we observe that the maximum radius ($R_{max}$) decreases with increasing anisotropy, which contrasts with the behavior at $g=10^{-5}$ and in scenarios with no DM. Our analysis indicates that binary pulsar systems could potentially constrain the extent of admixed anisotropic NS or, more optimistically, provide evidence for the existence of DM-admixed anisotropic NS.

29 pages, 12 figures, 6 tables

References in corpus (40)

• Array Programming with NumPy
• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Advanced Virgo: a 2nd generation interferometric gravitational wave detector
• Shapiro delay measurement of a two solar mass neutron star
• A Massive Pulsar in a Compact Relativistic Binary
• GW190814: Gravitational Waves from the Coalescence of a 23 M${}_{\odot }$ Black Hole with a 2.6 M${}_{\odot }$ Compact Object
• PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter
• A NICER View of PSR J0030+0451: Millisecond Pulsar Parameter Estimation
• Chiral effective field theory and nuclear forces
• Constraining neutron star tidal Love numbers with gravitational wave detectors
• A NICER View of the Massive Pulsar PSR J0740+6620 Informed by Radio Timing and XMM-Newton Spectroscopy
• PSR J0952-0607: The Fastest and Heaviest Known Galactic Neutron Star
• Implications of PREX-II on the equation of state of neutron-rich matter
• WIMP Annihilation and Cooling of Neutron Stars
• Neutron Stars and the Nuclear Equation of State
• A class of relativistic stars with a linear equation of state
• An updated mass-radius analysis of the 2017-2018 NICER data set of PSR J0030+0451
• Bosonic Dark Matter in Neutron Stars and its Effect on Gravitational Wave Signal
• Dark matter admixed neutron stars
• Neutron star equilibrium configurations within a fully relativistic theory with strong, weak, electromagnetic, and gravitational interactions
• Gravitational effects of condensate dark matter on compact stellar objects
• The tidal deformability of an anisotropic compact star: Implications of GW170817
• Tidal Deformability of Dark Matter Admixed Neutron Stars
• Dark Matter or Regular Matter in Neutron Stars? How to tell the difference from the coalescence of compact objects
• The effects of self-interacting bosonic dark matter on neutron star properties
• Equilibrium Structure and Radial Oscillations of Dark Matter Admixed Neutron Stars
• Tidal Love Numbers of Novel and Admixed Celestial Objects
• Comprehensive study of compact stars with dark matter
• Influence of the crust on the neutron star macrophysical quantities and universal relations
• $I-$Love$-C$ relation for an anisotropic neutron star
• Anisotropic Strange Stars in the Spotlight: Unveiling Constraints through Observational Data
• Dark matter effects on the properties of neutron stars: compactness and tidal deformability
• Towards Uncovering Dark Matter Effects on Neutron Star Properties: A Machine Learning Approach
• Dark matter admixed neutron stars with a realistic nuclear equation of state from chiral nuclear interactions
• f-mode oscillations of anisotropic neutron stars in full general relativity
• Effects from Dark Matter Halos on X-ray Pulsar Pulse Profiles
• Spherically symmetric anisotropic strange stars
• Constraining the Surface Curvature of an Anisotropic Neutron Star
• Role of local anisotropy in hybrid stars
• On exotic objects made of dark energy and dark matter: Mass-to-radius profiles and tidal Love numbers

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• Effects of light-mass fermionic dark matter on the equilibrium and stability of white dwarfs
• Neutron Star Equation of State with Nucleon Short-Range Correlations: A Concise Review and Open Issues
• Effects of short-range correlations at high densities on neutron stars with and without DM content: role of the repulsive self-interaction