Publication Date:
2013-12-06
Description:
We propose a two-parameter generalization for the dark energy equation of state (EOS) w X for thawing dark energy models which include PNGB, CPL and Algebraic thawing models as limiting cases and confront our model with the latest observational data namely Type Ia supernovae, observational Hubble data, cosmic microwave background, Baryon Oscillation Spectroscopic Survey data. Our analysis reveals that the phantom type of thawing dark energy is favoured up to 2 confidence level (CL). These results also show that thawing dark energy EOS is not unique from observational point of view. Though different thawing dark energy models are not distinguishable from each other from best-fitting values (up to 2 CLs) of matter density parameter ( $\Omega _{\rm m}^0$ ) and hubble parameter ( H 0 ) at the present epoch, best-fitting plots of linear growth of matter perturbation ( f ) and average deceleration parameter ( q av ); the difference indeed reflects in best-fitting variations of thawing dark energy EOS, model-independent geometrical diagnostics like the statefinder pair { r , s } and Om 3 parameter. We are thus led to the conclusion that unlike the standard observables ( $\Omega _{\rm m}^0$ , H 0 , f and q av ), the model-independent parameters ( r , s and Om 3) and the variations of EOS (in terms of $w_X{\rm -}w_X^{\prime }$ plots) serve as model discriminators for thawing dark energy models.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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