Quintessence and (Anti-)Chaplygin Gas in Loop Quantum Cosmology
  The concordance model of cosmology contains several unknown components such
as dark matter and dark energy. Many proposals have been made to describe them
by choosing an appropriate potential for a scalar field. We study four models
in the realm of loop quantum cosmology (LQC): the Chaplygin gas, an
inflationary and radiation-like potential, quintessence and an anti-Chaplygin
gas. For the latter we show that all trajectories start and end with a type II
singularity and, depending on the inital value, may go through a bounce. On the
other hand the evolution under the influence of the first three scalar fields
behaves classically at times far away from the big bang singularity and bounces
as the energy density approaches the critical density.
