Quintessence or Phantom: Study of scalar field dark energy models through a general parametrization of the Hubble parameter

Abstract

In this work we propose a simple general parametrization scheme of the Hubble parameter for the scalar field dark energy models. In our approach it is possible to incorporate both the quintessence and phantom scalar field in a single analytical scheme and write down relevant cosmological parameters which are independent of the nature of the scalar field. A general condition for the phantom barrier crossing has also been obtained. To test this approach, a well behaved parametrization of the normalized Hubble parameter has been considered and a wide variety of observational data like CMB data, Supernovae data, BAO data etc. has been used to constraint the various cosmological parameters. It has been found that data prefer the present value of the equation of state of the dark energy to be in the phantom domain. One interesting outcome of this analysis is that although the current value of the dark energy equation of state is phantom in nature, a phantom crossing of the EOS has taken place in the recent past. We have also carried out the Bayesian model comparison between ΛCDM model and the proposed model which indicates that this model is favored by data as compared to ΛCDM model.

Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies

“…Dropping the field interpretation of DE, it is possible to explore models in which DE sector deviates from the cosmological constant to a DE fluid with an extended EoS parameter w DE = −1, which can generally vary with redshift. These dynamical dark energy (DDE) models have been extensively studied in the literature [24,183,252,457,641,[728][729][730][731][732][733][734][735], based on considerations over the reconstruction of the effective w DE from data [183]. 16 DDE models typically solve the H 0 tension within two standard deviations at the price of a phantom-like DE, i.e.…”

Physical properties of a quintessence anisotropic stellar model in f(Q) gravity and the mass–radius relation

“…According to Agostino et al [33], if the thermodynamics for a generalized scalar (dark) matter field is expressed in terms of a quasi-quintessence representation, the vacuum energy contribution can be removed. For the scalar field dark energy models, Roy et al [34] suggested a simple generalized parameterization approach of the Hubble parameter. With their method, it is possible to write down relevant cosmological parameters that are independent of the scalar field's nature while incorporating both the quintessence and phantom scalar fields into a single analytical scheme.…”