Abstract We show that a phenomenological form of energy density for the scalar field can provide the required transition from decelerated (q > 0) to accelerated expansion (q < 0) phase of the universe. We have used the latest type Ia supernova (SNIa) and Hubble parameter datasets to constrain the model parameters. The best fit values obtained from those datasets are then applied to reconstruct ωφ(z), the equation of state parameter for the scalar field. The results show that the reconstructed forms of q(z) and ωφ(z) do not differ much from the standard ΛCDM value at the current epoch. Finally, the functional form of the relevant potential V(φ) is derived by a parametric reconstruction. The corresponding V(φ) comes out to be a double exponential potential, which has a number of cosmological implications. Additionally, we have also studied the effect of this particular scalar field dark energy sector on the evolution of matter overdensities.
Keywords cosmic acceleration — quintessence field — dark energy density — perturbation
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