Study of a viscous $\Lambda$WDM model: Near equilibrium condition, entropy production, and cosmological constraints

Abstract

Extensions to a $\Lambda$DM model have been explored to face current tensions that occur within its framework, which encompasses broadening the nature of the dark matter (DM) component to include warmness and a non-perfect fluid description. In this paper, we investigated the late-time cosmological evolution of an exact solution recently found in [N. Cruz, E. González, and J. Jovel, Phys. Rev. D \textbf{105}, 024047 (2022)], which describe a viscous warm $\Lambda$DM model ($\Lambda$WDM) with a DM component that obeys a polytropic equation of state (EoS), which experience dissipative effects with a bulk viscosity proportional to its energy density, with proportionality constant ${\xi }_0$. This solution has the particularity of having a very similar behavior to the $\Lambda$CDM model for small values of ${\xi }_0$, evolving also to a de Sitter type expansion in the very far future. We explore firstly the thermodynamic consistences of this solution in the framework of the Eckart's theory of non-perfect fluids, focusing on the fulfillment of the two following conditions: (i) the near equilibrium condition and (ii) the positiveness of the entropy production. We explore the range of parameters of the model that allow to fulfilling these two conditions at the same time, finding that a viscous WDM component is compatible with both ones, being in this sense, a viable model from the thermodynamic point of view. Besides, we constraint the free parameters of the model with the observational data coming form supernovae Ia (SNe Ia) and the observational Hubble parameter data (OHD).(Abridged)

16 pages, 6 figures

References in corpus (22)

• Large Magellanic Cloud Cepheid Standards Provide a 1% Foundation for the Determination of the Hubble Constant and Stronger Evidence for Physics Beyond LambdaCDM
• Correcting Type Ia Supernova Distances for Selection Biases and Contamination in Photometrically Identified Samples
• Viscous Cosmology for Early- and Late-Time Universe
• Opening a new window for warm dark matter
• Sterile neutrino dark matter as a consequence of nuMSM-induced lepton asymmetry
• Does Bulk Viscosity Create a Viable Unified Dark Matter Model?
• Using Pantheon and DES supernova, baryon acoustic oscillation, and Hubble parameter data to constrain the Hubble constant, dark energy dynamics, and spatial curvature
• Can a matter-dominated model with constant bulk viscosity drive the accelerated expansion of the universe?
• Constraints on the properties of warm dark matter using the satellite galaxies of the Milky Way
• Exploring a matter-dominated model with bulk viscosity to drive the accelerated expansion of the Universe
• Bulk Viscosity, Decaying Dark Matter, and the Cosmic Acceleration
• Cosmological bounds on the equation of state of dark matter
• Cosmic viscosity as a remedy for tension between PLANCK and LSS data
• Accelerated and decelerated expansion in a causal dissipative cosmology
• Characteristic Properties of Two Different Viscous Cosmology Models for the Future Universe
• Constraints and cosmography of $\Lambda$CDM in presence of viscosity
• Cosmology and thermodynamics of FRW universe with bulk viscous stiff fluid
• A hybrid model of viscous and Chaplygin gas to tackle the Universe acceleration
• Can the Hubble tension be resolved by bulk viscosity?
• Viscous universe with cosmological constant
• Exact solutions of a Flat Full Causal Bulk viscous FRW cosmological model through factorization
• Thermodynamic aspects of entropic cosmology with viscosity

Cited by in corpus (6)

• Quintessence Behaviour of an Anisotropic Bulk Viscous Cosmological Model in Modified $f(Q)$-Gravity
• A new Parametrization for Bulk Viscosity Cosmology as Extension of the $\Lambda$CDM Model
• A non-singular early-time viscous cosmological model
• WIMP dark matter in bulk viscous non-standard cosmologies
• FIMP Dark Matter in bulk viscous non-standard cosmologies
• Testing a nonlinear solution of the Israel-Stewart theory