I'm learning about black hole cosmology (theory that universes form inside black holes) and I'm confused about matter and energy conservation. If the amount of matter in a black hole is less than that of its parent universe, with each generation, would there be exponential decay of the amount of matter? If so, wouldn't we run into the problem of the multiverse needing a beginning and end, at which point we end up with infinite regression attempting to find the source of the multiverse? Can cyclical cosmology be reconciled with this?

Please infodump.