Thawing models in the presence of a generalized Chaplygin gas
  In this paper we consider a cosmological model whose main components are a
scalar field and a generalized Chaplygin gas. We obtain an exact solution for a
flat arbitrary potential. This solution have the right dust limit when the
Chaplygin parameter $A\rightarrow 0$. We use the dynamical systems approach in
order to describe the cosmological evolution of the mixture for an exponential
self-interacting scalar field potential. We study the scalar field with an
arbitrary self-interacting potential using the "Method of $f$-devisers." Our
results are illustrated for the special case of a coshlike potential. We find
that usual scalar-field-dominated and scaling solutions cannot be late-time
attractors in the presence of the Chaplygin gas (with $\alpha>0$). We recover
the standard results at the dust limit ($A\rightarrow 0$). In particular, for
the exponential potential, the late-time attractor is a pure generalized
Chaplygin solution mimicking an effective cosmological constant. In the case of
arbitrary potentials, the late-time attractors are de Sitter solutions in the
form of a cosmological constant, a pure generalized Chaplygin solution or a
continuum of solutions, when the scalar field and the Chaplygin gas densities
are of the same orders of magnitude. The different situations depend on the
parameter choices.
