there is no contraction for the BB cycle - matter is expelled from the moment of singularity at an acute angle, as a trajectory that returns the matter without changing direction at the same time back to the point of singularity as a mirror image of its initial expulsion. to recompact back to energy.
What in the world are you talking about? The standard Big Bang model is not a cyclic model at all, so of course there's no contraction, and the cosmological singularity of general relativity is a relic. The singularities I'm alluding to are those produced by the perturbations of contracting spacetimes. They arise in the wake of the contracting volume and, therefore, are "block" the expanding path of the rebound. On the Aguirre-Gratton scenario (2001), the arrows of time are reversed at
t = 0 in order to avoid them. It seems you're working off dated theory. The old oscillating models of the '60s, for example, assumed the theoretical effects of quantum gravity, which are thought to give, not a singularity, but a repulsive force such that there is a maximal compaction of ordinary matter at the Planck scale. On these models, each expansion phase is preceded by a contraction phase, which was asserted as a brute fact, though it be paradoxical. The idea was to evade the thermodynamic ramifications of cyclic cosmogonies that begin with an expansion phase. But all of that was before inflationary theory. It's cosmic inflation that puts the bang in the Big Bang. The notion of an initial, cosmological singularity at the boundary is passé.