Constraining Red-shift Parametrization Parameters in Brans-Dicke Theory: Evolution of Open Confidence Contours

Abstract

In Brans Dicke theory of gravity, from the nature of the scalar field-potential considered, the dark energy, dark matter, radiation densities predicted by different observations and the closedness of the universe considered, we can fix our ${\omega }_{BD}$, the Brans Dicke parameter, keeping only the thing in mind that from different solar system constrains it must be greater than $5\times 10^5$. Once we have a value, satisfying the required lower boundary, in our hand we proceed for setting unknown parameters of the different dark energy models' EoS parameter. In this paper we work with three well known red shift parametrizations of dark energy EoS. To constrain their free parameters for Brans Dicke theory of gravity we take twelve point red shift vs Hubble's parameter data and perform ${\chi }^2$ test. We present the observational data analysis mechanism for Stern, Stern+BAO and Stern+BAO+CMB observations. Minimising ${\chi }^2$, we obtain the best fit values and draw different confidence contours. We analyze the contours physically. Also we examine the best fit of distance modulus for our theoretical models and the Supernovae Type Ia Union2 sample. For Brans Dicke theory of gravity the difference from the mainstream confidence contouring method of data analysis id that the confidence contours evolved are not at all closed contours like a circle or a ellipse. Rather they are found to be open contours allowing the free parameters to float inside a infinite region of parameter space. However, negative EoSs are likely to evolve from the best fit values.

13 Pages, 12 Figures. arXiv admin note: substantial text overlap with arXiv:1304.6713 by other authors

References in corpus (12)

• 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
• Cosmological parameters from combining the Lyman-alpha forest with CMB, galaxy clustering and SN constraints
• WMAP constraints on low redshift evolution of dark energy
• Generalized Chaplygin gas model: constraints from Hubble parameter versus Redshift Data
• Brans-Dicke Theory as a Unified Model for Dark Matter - Dark Energy
• A test of the CPL parameterization for rapid dark energy equation of state transitions
• Thermodynamics of charged rotating black branes in Brans-Dicke theory with quadratic scalar field potential
• Dynamical complexity of the Brans-Dicke cosmology
• Role of Brans-Dicke Theory with or without self-interacting potential in cosmic acceleration
• Scalar field mass in generalized gravity
• High energy description of dark energy in an approximate 3-brane Brans-Dicke cosmology

Cited by in corpus (1)

• Barboza-Alcaniz Equation of State Parametrization : Constraining the Parameters in Different Gravity Theories