My question is do baby universes give us a satisfying explanation of the black hole information paradox without violating thermodynamics, or any other established/known physics?
My understanding is that it wouldn’t contradict unitarity because, while information is “lost” from our perspective outside of the black hole, unitarity is obeyed in the multiverse, of which observers only have partial knowledge. So for example in arxiv:0901.3156, Sabine Hossenfelder and Lee Smolin consider it a conservative solution.
So according to this scenario universes are spawned through black holes, they “emerge” on the other side through white holes. But if white holes are time reversed black holes (CPT symmetry), then since entropy increases as the area of a black hole increases then does entropy decrease in a white hole? If the area decrease coincides with the increase in entropy then surely that contradicts the holographic entropy bound?
I think there’s got to be a mistake in my comment but I’m not sure, thanks for any responses.