I recently read a few articles that contradict Einstein's Singularity theorem. The idea being that black holes are wormholes to other universes; with a white hole on the other side of the black hole (Poplawski's theory). What if instead of being a portal to another universe, the Event Horizon of a black hole is the physical edge to a universe. I'm hardly a professional physicist and have little to none experience with calculus, so I was wondering if anyone knows of anyone who has tried to calculate: The average expansion rate of an Event Horizon, in comparison to, our universes expansion rate but to the scale of an average Event Horizon. Would this calculation provide evidence for this theory? Any feedback would be much appreciated.