Red-shift parametrizations of dark energy and observational constraint on their parameters: Galileon gravity as background

Abstract

In this work, FRW universe filled with dark matter (perfect fluid with negligible pressure) along with dark energy in the background of Galileon gravity is considered. Four dark energy models with different EoS parametrizations have been employed namely, Linear, CPL, JBP and Logarithmic parametrizations. From Stern, Stern+BAO and Stern+BAO+CMB joint data analysis, we have obtained the bounds of the arbitrary parameters ${\omega }_0$ and ${\omega }_1$ by minimizing the ${\chi }^2$ test. The best-fit values and bounds of the parameters are obtained at 66\%, 90\% and 99\% confidence levels which are shown by closed confidence contours in the figures. For the logarithmic model unbounded confidence contours are obtained and hence the model parameters could not be finitely constrained. The distance modulus $\mu$(z) against redshift $z$ has also been plotted for our predicted theoretical models for the best fit values of the parameters and compared with the observed Union2 data sample and SNe Type Ia 292 data and we have shown that our predicted theoretical models permits the observational data sets. From the data fitting it is seen that at lower redshifts $(z<0.3)$ the SNe Type Ia 292 data gives a better fit with our theoretical models compared to the Union2 data sample. So, from the data analysis, SNe Type Ia 292 data is the more favoured data sample over its counterpart given the present choice of free parameters. From the study, it is also seen that the logarithmic parametrization model is less supported by the observational data. Finally we have generated the plot for the deceleration parameter against the redshift parameter for all the theoretical models and compared the results with the work of Farooq et al, 2013.

16 pages, 19 figures, Accepted for publication in Mod. Phys. Letts. A. arXiv admin note: substantial text overlap with arXiv:1406.3043, arXiv:1206.0507, arXiv:1304.6713

References in corpus (17)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
• 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
• Covariant Galileon
• Membranes at Quantum Criticality
• Generalized Galileons: All scalar models whose curved background extensions maintain second-order field equations and stress tensors
• Cosmological parameters from combining the Lyman-alpha forest with CMB, galaxy clustering and SN constraints
• A Dark Energy Model Characterized by the Age of the Universe
• A New Model of Agegraphic Dark Energy
• WMAP constraints on low redshift evolution of dark energy
• Galileon Cosmology
• Constraints on modified Chaplygin gas from recent observations and a comparison of its status with other models
• Observational Constraints of Modified Chaplygin Gas in Loop Quantum Cosmology
• Study of Some Parameters of Modified Chaplygin Gas in Galileon Gravity Theory from Observational Perspective
• Observational Constraints of Modified Chaplygin Gas in RS II Brane
• Constraining Parameters of Generalized Cosmic Chaplygin Gas in Loop Quantum Cosmology

Cited by in corpus (2)

• Phase space of static wormholes sustained by an isotropic perfect fluid
• Extended datasamples under the lens of Brane World Theory