Study of parametrized dark energy models with a general non-canonical scalar field

Dec 11, 2015
20 pages
Published in:
  • Eur.Phys.J.C 76 (2016) 3, 135
  • Published: Mar 11, 2016
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Abstract: (Springer)
In this paper, we consider various dark energy models in the framework of a non-canonical scalar field with a Lagrangian density of the form L(ϕ,X)=f(ϕ)X(XM4Pl)α1V(ϕ)\mathcal{L}(\phi , X)=f(\phi )X{\left( \frac{X}{M^{4Pl}}\right) }^{\alpha -1} - V(\phi ) , which provides the standard canonical scalar field model for α=1\alpha =1 and f(ϕ)=1f(\phi )=1 . In this particular non-canonical scalar field model, we carry out the analysis for α=2\alpha =2 . We then obtain cosmological solutions for constant as well as variable equation of state parameter ( ωϕ(z)\omega _{\phi }(z) ) for dark energy. We also perform the data analysis for three different functional forms of ωϕ(z)\omega _{\phi }(z) by using the combination of SN Ia, BAO, and CMB datasets. We have found that for all the choices of ωϕ(z)\omega _{\phi }(z) , the SN Ia ++ CMB/BAO dataset favors the past decelerated and recent accelerated expansion phase of the universe. Furthermore, using the combined dataset, we have observed that the reconstructed results of ωϕ(z)\omega _{\phi }(z) and q(z) are almost choice independent and the resulting cosmological scenarios are in good agreement with the Λ\Lambda CDM model (within the 1σ1\sigma confidence contour). We have also derived the form of the potentials for each model and the resulting potentials are found to be a quartic potential for constant ωϕ\omega _{\phi } and a polynomial in ϕ\phi for variable ωϕ\omega _{\phi } .
Note:
  • 22 pages, 13 figures
  • 98.80.Hw
  • parametrization
  • dark energy
  • cosmic background radiation
  • cosmological model
  • equation of state
  • deceleration
  • statistical