Spherical `Top-Hat' Collapse in general Chaplygin gas dominated universes

We expand previous works on the spherical ‘top-hat’ collapse (SC-TH) framework in generalized Chaplygin gas (gCg) dominated universes. Here we allow the collapse in all energetic components within the system. We analyze the non-linear stages of collapse for various choices of parameter � of the gCg model introducing an exact formulation for the so-called effective sound speed, c 2 . We show that, within the SC-TH framework, the growth of the structure becomes faster with increasing values of �. This partially contradicts previous results obtained using an approximation in the context of linear perturbation theory.