Cosmology with hybrid expansion law: scalar field reconstruction of
  cosmic history and observational constraints
  In this paper, we consider a simple form of expansion history of Universe
referred to as the hybrid expansion law - a product of power-law and
exponential type of functions. The ansatz by construction mimics the power-law
and de Sitter cosmologies as special cases but also provides an elegant
description of the transition from deceleration to cosmic acceleration. We
point out the Brans-Dicke realization of the cosmic history under
consideration. We construct potentials for quintessence, phantom and tachyon
fields, which can give rise to the hybrid expansion law in general relativity.
We investigate observational constraints on the model with hybrid expansion law
applied to late time acceleration as well as to early universe a la
nucleosynthesis.
