The nature of gravitation and spatial expansion leave lingering questions which might be neatly resolved with the inclusion of an anti-universe.
When we artificially create antimatter it comes into existence embedded within a field of positive time dilation allowing very rapid annihilation. At BB there is a concievable sequence of consequences intervening with annihilation. Firstly the articulation of two infinite fields represents a distinguishment of momentum on the global scale. Providing an antimatter universe answers the question of where the universe is going by suggesting that the instantaneous dilation of two universal time fields has forced a separation between the two so violent that annihilation has simply been delayed for a considerable brevity. In this scenario heat death of the universe allows an internal relativity within each universe so uniform the two come crashing back together to anhilate so violently the question of where the energy for a BB might come from seems rhetorical.
It appears to be a question of SR. At BB, for GR to be established SR has to first be definitive. The moment matter and antimatter come into existence requires that the two fields are substantially seperated by necessity. The relativity between particles within each field becomes a trade off with the relativity between the two distinguished fields. It may be that what is missing from a complete standard theory is not a balance of forces but a balance of relativities.
Subsequently the purpose of this thread would be to properly define a relativity between these two oppositional fields that is complimentary and definitive of SR and GR. Under this scenario c becomes a measure of the suspension between the two fields.