Results 31 to 40 of about 106,793 (315)
Scalar-field theory of dark matter [PDF]
International Journal of Modern Physics A, 2014 We develop a theory of dark matter based on a previously proposed picture, in which a complex vacuum scalar field makes the universe a superfluid, with the energy density of the superfluid giving rise to dark energy, and variations from vacuum density giving rise to dark matter. We formulate a nonlinear Klein–Gordon equation to describe the superfluid,
Xiaofei Zhao, Kerson Huang, Chi Xiong
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UNIFIED DARK MATTER IN SCALAR FIELD COSMOLOGIES [PDF]
Modern Physics Letters A, 2007 Considering the general Lagrangian of k-essence models, we study and classify them through variables connected to the fluid equation of state parameter wκ. This allows one to find solutions around which the scalar field describes a mixture of dark matter and cosmological constant-like dark energy, an example being the purely kinetic model proposed by ...
BERTACCA, DANIELE +2 more
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Halos of unified dark matter scalar field [PDF]
Journal of Cosmology and Astroparticle Physics, 2008 We investigate the static and spherically symmetric solutions of Einstein's equations for a scalar field with non-canonical kinetic term, assumed to provide both the dark matter and dark energy components of the Universe. In particular, we give a prescription to obtain solutions (dark halos) whose rotation curve v_c(r) is in good agreement with ...
BERTACCA, DANIELE +2 more
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Scalar field dark matter in hybrid approach [PDF]
Physical Review D, 2017 This version matches the one accepted for publication in Physical Review D.
Friedrich, Pavel, Prokopec, Tomislav
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Universe, 2020 The generalized hybrid metric-Palatini theory of gravity admits a scalar-tensor representation in terms of two interacting scalar fields. We show that, upon an appropriate choice of the interaction potential, one of the scalar fields behaves like dark ...
Paulo M. Sá
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Stability of Cauchy horizon in a charged de-Sitter spacetime with dark matter
European Physical Journal C: Particles and Fields, 2023 The violation of strong cosmic censorship (SCC) in RNdS black holes by a minimally coupled neutral massless scalar field has recently been discovered. This paper investigates the stability of the Cauchy horizon of a spherically charged de-Sitter black ...
Xue-Ying Nan, Jia Tan, Jie Jiang
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Dark sector impact on gravitational collapse of an electrically charged scalar field [PDF]
, 2015 Dark matter and dark energy are dominating components of the Universe. Their presence affects the course and results of processes, which are driven by the gravitational interaction.
Nakonieczna, Anna +2 more
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Is Dark Matter a BEC or Scalar Field? [PDF]
Journal of the Korean Physical Society, 2009 This is a brief review on the history of the Bose-Einstein condensate (BEC) or boson star model of galactic dark matter halos, where ultra-light scalar dark matter particles condense in a single BEC quantum state. The halos can be described as a self-gravitating, possibly self-interacting, coherent scalar field.
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Pulsar timing residual induced by ultralight vector dark matter
European Physical Journal C: Particles and Fields, 2020 We study the ultralight vector dark matter with a mass around $$10^{-23}\,\mathrm {eV}$$ 10-23eV . The vector field oscillating coherently on galactic scales induces oscillations of the spacetime metric with a frequency around nHz, which is detectable by
Kimihiro Nomura, Asuka Ito, Jiro Soda
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Scale-invariant scalar field dark matter through the Higgs portal
Journal of High Energy Physics, 2018 We discuss the dynamics and phenomenology of an oscillating scalar field coupled to the Higgs boson that accounts for the dark matter in the Universe. The model assumes an underlying scale invariance such that the scalar field only acquires mass after ...
Catarina Cosme +2 more
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