  Cosmologies with a Chaplygin gas have recently been explored with the
objective of explaining the transition from a dust dominated epoch towards an
accelerating expansion stage. We consider the hypothesis that the transition to
the accelerated period involves a quantum mechanical process. Three physically
admissible cases are possible. In particular, we identify a minisuperspace
configuration with two Lorentzian sectors, separated by a classically forbidden
region. The Hartle-Hawking and Vilenkin wave functions are computed, together
with the transition amplitudes towards the accelerating epoch. Furthermore, it
is found that for specific initial conditions, the parameters characterizing
the generalized Chaplygin gas become related through an expression involving an
integer $n$. We also introduce a phenomenological association between some
brane-world scenarios and a FRW minisuperspace cosmology with a generalized
Chaplygin gas. The aim is to promote a discussion and subsequent research on
the quantum creation of brane cosmologies from such a perspective. Results
suggest that the brane tension would become related with generalized Chaplygin
gas parameters through another expression involving an integer.
