1210.2565 (Debabrata Adak et al.)

Generalizing thawing dark energy models: the standard vis-à-vis model independent diagnostics    [PDF]

Debabrata Adak, Debasish Majumdar, Supratik Pal

We propose a two parameter generalization for the dark energy equation of state (EOS) for thawing dark energy models, which includes PNGB, CPL and algerbraic thawing models as limiting cases; and confront our model with latest Supernova Type Ia (SNe Ia) Data from Union 2.1 compilation, latest Observational Hubble Data (OHD), Cosmic Microwave Background (CMB) Data from 7 year WMAP results and latest Baryon Acoustic Oscillation Data from SDSS Data Release 9 to constrain our parameter space. The analysis reveals that thawing dark energy EOS is not unique from the observational point of view so far as the standard parameters (dark energy EOS, present value of matter density parameter and Hubble parameter) are concerned. In other words, different thawing dark energy models are not distinguishable from each other with the help of best-fit values of matter density parameter at present epoch, linear growth of matter perturbation and the average deceleration parameter. But tuning the model parameters does leave its impact on the variation of dark energy EOS as well as the model-independent parameters like the statefinder pair and $Om3$ parameters. We are thus led to the conclusion that unlike the standard parameters, the model-independent parameters and the variation of EOS serve as model discriminators for different thawing dark energy models.

View original: http://arxiv.org/abs/1210.2565