Reconstructing cosmic evolution with a density parametrization

Abstract

The current paper provides a comprehensive examination of a dark energy cosmological model in the classical regime, in which a generic scalar field is regarded as a dark energy source. Einstein's field equations are solved in model independent way i.e. using a scheme of cosmological parametrization. A parametrization of the density parameter as a function of the cosmic scale factor has been investigated in this line. The result is noteworthy because it shows a smooth transition from a decelerating to an accelerating phase in the recent past. The model parameters involved in the functional form of the parametrization approach utilized here were constrained using certain external datasets. The updated Hubble datasets containing 57 datapoints, 1048 points of recently compiled Pantheon datasets, and also the Baryon Acoustic Oscillation (BAO) datasets are used here to determine the best-fitting model parameter values. The expressions of several significant cosmological parameters are represented as a function of redshift `$z$' and illustrated visually for the best fit values of the model parameters to better comprehend cosmic evolution. The obtained model is also compared with the $\Lambda CDM$ model. Our model has a distinct behavior in future and shown a big crunch type collapse. The best fit values of the model parameters are also used to compute the current values of several physical and geometrical parameters, as well as phase transition redshift. To examine the nature of dark energy, certain cosmological tests and diagnostic analyses are done on the derived model.

19 pages, 12 figures with sub figures

References in corpus (14)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Dynamics of dark energy
• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• Raising the bar: new constraints on the Hubble parameter with cosmic chronometers at z$\sim$2
• Baryon Acoustic Oscillations in the Lyα forest of BOSS DR11 quasars
• Cosmological Evolution of a Quintom Model of Dark Energy
• Two new diagnostics of dark energy
• Baryon Acoustic Oscillations in the Ly-α forest of BOSS quasars
• General Relativity and Cosmology: Unsolved Questions and Future Directions
• Cosmic acceleration with bulk viscosity in modified $f(Q)$ gravity
• Modified gravity a la Galileon: Late time cosmic acceleration and observational constraints
• Shape invariance method for quintom model in the bent brane background
• Late-time acceleration with a scalar field source: Observational constraints and statefinder diagnostics
• Statistics of Thawing K-essence Dark Energy Models