Observational constraints on scalar field models of dark energy with barotropic equation of state

Abstract

We constrain the parameters of dynamical dark energy in the form of a classical or tachyonic scalar field with barotropic equation of state jointly with other cosmological ones using the combined datasets which include the CMB power spectra from WMAP7, the baryon acoustic oscillations in the space distribution of galaxies from SDSS DR7, the power spectrum of luminous red galaxies from SDSS DR7 and the light curves of SN Ia from 2 different compilations: Union2 (SALT2 light curve fitting) and SDSS (SALT2 and MLCS2k2 light curve fittings). It has been found that the initial value of dark energy equation of state parameter is constrained very weakly by most of the data while the rest of main cosmological parameters are well constrained: their likelihoods and posteriors are similar, have the forms close to Gaussian (or half-Gaussian) and their confidential ranges are narrow. The most reliable determinations of the best fitting value and $1\sigma$ confidence range for the initial value of dark energy equation of state parameter were obtained from the combined datasets including SN Ia data from the full SDSS compilation with MLCS2k2 fitting of light curves. In all such cases the best fitting value of this parameter is lower than the value of corresponding parameter for current epoch. Such dark energy loses its repulsive properties and in future the expansion of the Universe will change into contraction. We also perform an error forecast for the Planck mock data and show that they narrow essentially the confidential ranges of cosmological parameters values, moreover, their combination with SN SDSS compilation with MLCS2k2 light curve fitting may exclude the fields with initial equation of state parameter $>-0.1$ at 2$\sigma$ confidential level.

26 pages, 13 figures, 4 tables, accepted for publication in JCAP

References in corpus (19)

• Dynamics of dark energy
• Dark Energy and the Accelerating Universe
• Baryon Acoustic Oscillations in the Sloan Digital Sky Survey Data Release 7 Galaxy Sample
• Improved Cosmological Constraints from New, Old and Combined Supernova Datasets
• Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Power Spectra and WMAP-Derived Parameters
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Sky Maps, Systematic Errors, and Basic Results
• Improved Distances to Type Ia Supernovae with Multicolor Light Curve Shapes: MLCS2k2
• First-year Sloan Digital Sky Survey-II (SDSS-II) Supernova Results: Hubble Diagram and Cosmological Parameters
• Primordial Nucleosynthesis in the Precision Cosmology Era
• Cosmological Constraints from the Clustering of the Sloan Digital Sky Survey DR7 Luminous Red Galaxies
• Probing cosmological parameters with the CMB: Forecasts from full Monte Carlo simulations
• Cosmic Acceleration, Dark Energy and Fundamental Physics
• Dark Energy in Practice
• Evidence for the Fifth Element Astrophysical status of Dark Energy
• Properties and uncertainties of scalar field models of dark energy with barotropic equation of state
• Perturbed dark energy: classical scalar field versus tachyon
• Constraining Models of Dark Energy
• Scalar field models of dark energy with barotropic equation of state: properties and observational constraints from different datasets

Cited by in corpus (13)

• Dynamical dark energy after Planck CMB final release and $H_0$ tension
• Do the cosmological observational data prefer phantom dark energy?
• Abell 2744: Too much substructure for Lambda CDM?
• On the Stability of Einstein Static Universe in Doubly General Relativity Scenario
• Constraining the dynamical dark energy parameters: Planck-2013 vs WMAP9
• Sound speed of scalar field dark energy: weak effects and large uncertainties
• Rigorous theoretical constraint on constant negative EoS parameter $\omega$ and its effect for the late Universe
• Quintessence versus phantom dark energy: the arbitrating power of current and future observations
• Screening Mechanism and Late-time Cosmology: Role of a Chameleon-Brans-Dicke Scalar Field
• Combined cosmological tests of a bivalent tachyonic dark energy scalar field model
• Scalar field vs hydrodynamic models in the homogeneous isotropic cosmology
• Gravitational stability of dark energy in galaxies and clusters of galaxies
• Criticality and Big Brake singularities in the tachyonic evolutions of closed Friedmann universes with cold dark matter