Equilibrium Structure and Radial Oscillations of Dark Matter Admixed Neutron Stars

Abstract

In [Leung et al., Phys. Rev. D 84, 107301 (2011)], we presented our results on using a general relativistic two-fluid formalism to study the hydrostatic equilibrium configuration of an admixture of degenerate dark matter and normal nuclear matter. In this work, we present more analysis to complement our previous findings. We study the radial oscillation modes of these compact stars in detail. We find that these stars in general have two classes of oscillation modes. For a given total mass of the star, the first class of modes is insensitive to the dark-matter particle mass. They also reduce properly to the oscillation modes of the corresponding ordinary neutron star, with the same total mass, when the mass fraction of dark matter tends to zero. On the other hand, the second class of modes is due mainly to the dark-matter fluid. In the small dark-matter mass fraction limit, these modes are characterized purely by the oscillations of dark matter, while the normal matter is essentially at rest. In the intermediate regime where the mass fractions of the two fluids are comparable, the normal matter oscillates with the dark matter due to their coupling through gravity. In contrast to the first class of modes, the frequencies of these dark-matter dominated modes depend sensitively on the mass of dark-matter particles.

11 pages, 18 figures. Minor changes to match the published version

References in corpus (12)

• First results from DAMA/LIBRA and the combined results with DAMA/NaI
• Results from a Search for Light-Mass Dark Matter with a P-type Point Contact Germanium Detector
• Asymmetric Dark Matter
• Results from a Low-Energy Analysis of the CDMS II Germanium Data
• First Dark Matter Results from the XENON100 Experiment
• WIMP Annihilation and Cooling of Neutron Stars
• Compact Stars as Dark Matter Probes
• Dark matter and the first stars: a new phase of stellar evolution
• Dark matter in the solar system I: The distribution function of WIMPs at the Earth from solar capture
• Light WIMPs in the Sun: Constraints from Helioseismology
• Signatures of dark matter burning in nuclear star clusters
• Phenomenological constraints on accretion of non-annihilating dark matter on the PSR B1257+12 pulsar from orbital dynamics of its planets

Cited by in corpus (11)

• Tidal Deformability of Dark Matter Admixed Neutron Stars
• Radial oscillations of strange quark stars admixed with condensed dark matter
• First asteroseismic limits on the nature of dark matter
• Study of Dark-Matter Admixed Neutron Stars using the Equation of State from the Rotational Curves of Galaxies
• Radial oscillations and stability of multiple-fluid compact stars
• Dynamical evolution of dark matter admixed neutron stars
• Boson stars and their radial oscillations
• Does Dark Matter admixed pulsar exist ?
• Astrophysical aspects of milli-charged dark matter in a Higgs-Stueckelberg model
• The Sterile-Active Neutrino Flavor Model: the Imprint of Dark Matter on the Electron Neutrino Spectra
• Some properties of doubly-degenerate stars