Abstract
We study the effect of shear and rotation on results previously obtained dealing with the application of the spherical collapse model (SCM) to generalized Chaplygin gas (gCg)-dominated universes. The system is composed of baryons and gCg and the collapse is studied for different values of the parameter of the gCg. We show that the joint effect of shear and rotation is that of slowing down the collapse with respect to the simple SCM. This result is of utmost importance for the so-called unified dark matter models, since the described slowdown in the growth of density perturbations can solve one of the main problems of the quoted models, namely the instability described in previous papers [e.g., H. B. Sandvik et al., Phys. Rev. D 69, 123524 (2004)] at the linear perturbation level.
- Received 5 September 2012
DOI:https://doi.org/10.1103/PhysRevD.87.043527
© 2013 American Physical Society
