Constraints on reconstructed dark energy model from SN Ia and BAO/CMB
  observations
  The motivation of the present work is to reconstruct a dark energy model
through the {\it dimensionless dark energy function} $X(z)$, which is the dark
energy density in units of its present value. In this paper, we have shown that
a scalar field $\phi$ having a phenomenologically chosen $X(z)$ can give rise
to a transition from a decelerated to an accelerated phase of expansion for the
universe. We have examined the possibility of constraining various cosmological
parameters (such as the deceleration parameter and the effective equation of
state parameter) by comparing our theoretical model with the latest Type Ia
Supernova (SN Ia), Baryon Acoustic Oscillations (BAO) and Cosmic Microwave
Background (CMB) radiation observations. Using the joint analysis of the SN
Ia+BAO/CMB dataset, we have also reconstructed the scalar potential from the
parametrized $X(z)$. The relevant potential is found, which comes to be a
polynomial in $\phi$. From our analysis, it has been found that the present
model favors the standard $\Lambda$CDM model within $1\sigma$ confidence level.
