Structure formation in a $\Lambda$ $viscous$ CDM universe

Abstract

The possibility of dark matter being a dissipative component represents an option for the standard view where cold dark matter (CDM) particles behave on large scales as an ideal fluid. By including a physical mechanism to the dark matter description like viscosity we construct a more realistic model for the universe. Also, the known small scale pathologies of the standard CDM model either disappear or become less severe. We study clustering properties of a $\Lambda$CDM-like model in which dark matter is described as a bulk viscous fluid. The linear power spectrum, the nonlinear spherical "top hat" collapse and the mass functions are presented. We use the analysis with such structure formation tools in order to place an upper bound on the magnitude of the dark matter's viscosity.

7 pages, 6 figures

References in corpus (5)

• Does Bulk Viscosity Create a Viable Unified Dark Matter Model?
• Structure formation in the presence of dark energy perturbations
• Bulk Viscosity, Decaying Dark Matter, and the Cosmic Acceleration
• Dissipation of dark matter
• Non-adiabatic dark fluid cosmology

Cited by in corpus (6)

• Phase Space Analysis of the Accelerating Multi-fluid Universe
• Cosmic viscosity as a remedy for tension between PLANCK and LSS data
• On the implementation of the spherical collapse model for dark energy models
• Crossing the phantom divide with dissipative normal matter in the Israel-Stewart-Hiscock formalism
• Revealing the non-adiabatic nature of dark energy perturbations from galaxy clustering data
• Brazilian Community Report on Dark Matter