One-parameter dynamical dark-energy from the generalized Chaplygin gas

Abstract

The fact that Einstein's equations connect the space-time geometry to the total matter content of the cosmic substratum, but not to individual contributions of the matter species, can be translated into a degeneracy in the cosmological dark sector. Such degeneracy makes it impossible to distinguish cases where dark energy (DE) interacts with dark matter (DM) from a dynamical non-interacting scenario using observational data based only on time or distance measurements. In this paper, based on the non-adiabatic generalized Chaplygin gas (gCg) model, we derive and study some cosmological consequences of a varying one-parameter dynamical DE parameterization, which does not allow phantom crossing. We perform a parameter selection using the most recent public available data, such as the data from Planck 2018, eBOSS DR16, Pantheon and KiDS-1000. We find that current observations provide strong constraints on the model parameters, leading to values very close to the $\Lambda$CDM cosmology, at the same time that the well-known ${\sigma }_8$ tension is reduced from $\sim 3\sigma$ to $\sim 1\sigma$ level.

18 pages, 5 figures, LaTeX

References in corpus (16)

• The Clustering of the SDSS DR7 Main Galaxy Sample I: A 4 per cent Distance Measure at z=0.15
• Cosmic Distances Calibrated to 1% Precision with Gaia EDR3 Parallaxes and Hubble Space Telescope Photometry of 75 Milky Way Cepheids Confirm Tension with LambdaCDM
• The fourth data release of the Kilo-Degree Survey: ugri imaging and nine-band optical-IR photometry over 1000 square degrees
• Aspects of the cosmological "coincidence problem"
• Dark Energy and Dark Gravity
• A parametric model for dark energy
• Cluster Cepheids with High Precision Gaia Parallaxes, Low Zeropoint Uncertainties, and Hubble Space Telescope Photometry
• Gauge-invariant analysis of perturbations in Chaplygin gas unified models of dark matter and dark energy
• Cosmological constraints on a decomposed Chaplygin gas
• Inhomogeneous vacuum energy
• Non-adiabatic dark fluid cosmology
• Post-$Planck$ constraints on interacting vacuum energy
• Dark degeneracy I: Dynamical or interacting dark energy?
• CMB and matter power spectra with non-linear dark-sector interactions
• A Test of the Standard Cosmological Model with Geometry and Growth
• A Cautionary Tale: Dark Energy in Single-Field, Slow-Roll Inflationary Models

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• Equivalence of Dark Energy Models: A Theoretical and Bayesian Perspective
• Interacting dark sector with quadratic coupling: theoretical and observational viability