Viscosity in cosmic fluids

Abstract

The effective theory of large-scale structure formation based on $\Lambda$CDM paradigm predicts finite dissipative effects in the resulting fluid equations. In this work, we study how viscous effect that could arise if one includes self-interaction among the dark-matter particles combines with the effective theory. It is shown that these two possible sources of dissipation can operate together in a cosmic fluid and the interplay between them can play an important role in determining dynamics of the cosmic fluid. In particular, we demonstrate that the viscosity coefficient due to self-interaction is added inversely with the viscosity calculated using effective theory of $\Lambda$CDM model. Thus the larger viscosity has less significant contribution in the effective viscosity. Using the known bounds on $\sigma /m$ for self-interacting dark-matter, where $\sigma$ and $m$ are the cross-section and mass of the dark-matter particles respectively, we discuss role of the effective viscosity in various cosmological scenarios.

arXiv comment7 pages, Updated to match with the published version

References in corpus (43)

• Dark Matter Substructure in Galactic Halos
• Where are the missing galactic satellites?
• Observational evidence for self-interacting cold dark matter
• Cosmological Perturbation Theory in the Synchronous vs. Conformal Newtonian Gauge
• Cosmological Perturbation Theory in the Synchronous and Conformal Newtonian Gauges
• Small-Scale Challenges to the $\Lambda$CDM Paradigm
• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• Dark Matter Self-interactions and Small Scale Structure
• Resolving Cosmic Structure Formation with the Millennium-II Simulation
• The Core-Cusp Problem
• The Milky Way's bright satellites as an apparent failure of LCDM
• Cosmological Non-Linearities as an Effective Fluid
• Dark Matter Halos as Particle Colliders: A Unified Solution to Small-Scale Structure Puzzles from Dwarfs to Clusters
• Evolution of structure in cold dark matter universes
• Viscous Cosmology for Early- and Late-Time Universe
• High-resolution rotation curves of low surface brightness galaxies: Data
• Signs of Dark Matter at 21-cm?
• Heating of Baryons due to Scattering with Dark Matter During the Dark Ages
• Dark goo: Bulk viscosity as an alternative to dark energy
• Massive Neutrinos in Cosmology: Analytic Solutions and Fluid Approximation
• Bias Loop Corrections to the Galaxy Bispectrum
• Self-interacting Warm Dark Matter
• Dissipative properties of hot and dense hadronic matter in excluded volume hadron resonance gas model
• The Peculiar Velocity Function of Galaxy Clusters
• Cosmic viscosity as a remedy for tension between PLANCK and LSS data
• Accelerating cosmological expansion from shear and bulk viscosity
• Viscous dark matter growth in (neo-)Newtonian cosmology
• Constraints on cosmological viscosity and self interacting dark matter from gravitational wave observations
• The Metal-Poor Stellar Halo in RAVE-TGAS and its Implications for the Velocity Distribution of Dark Matter
• Viscous dark matter and 21 cm cosmology
• Power spectrum for the small-scale Universe
• Viscous Self Interacting Dark Matter and Cosmic Acceleration
• Assessing the impact of bulk and shear viscosities on large scale structure formation
• Boltzmann-Fokker-Planck formalism for dark-matter--baryon scattering
• A conventional approach to the dark-energy concept
• Bounds on Neutrino Mass in Viscous Cosmology
• Baryon-Dark matter interaction in presence of magnetic fields in light of EDGES signal
• Viscous Self Interacting Dark Matter Cosmology For Small Redshift
• Damping of gravitational waves in a viscous Universe and its implication for dark matter self-interactions
• Power Spectrum of Velocity Fluctuations in the Universe
• Anomalous viscosity of an expanding quark-gluon plasma
• Can neutrino viscosity drive the late time cosmic acceleration?
• Analytic expressions for the second-order scalar perturbations in the $\Lambda$CDM Universe within the cosmic screening approach

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• A new Parametrization for Bulk Viscosity Cosmology as Extension of the $\Lambda$CDM Model
• Global 21-cm brightness temperature in viscous dark energy models
• Magnetohydrodynamic instabilities in a self-gravitating rotating cosmic plasma
• Bounds on sterile neutrino lifetime and mixing angle with active neutrinos by global 21 cm signal
• Viscous attenuation of gravitational waves propagating through an inhomogeneous background
• Gravitational Wave luminosity distance in viscous cosmological models
• Lightening the Dark Matter from its Viscosity and Explanation of EDGES Anomaly