If white holes exist that are the inverse of black holes. The universe could exist forever. Black holes would suck matter in and white wholes on the other side would create new matter on the other side.

Black wholes and white holes would then be gateways to other universes.

Multi verse https://en.wikipedia.org/wiki/Multiverse

https://news.nationalgeographic.com/news/2010/04/100409-blac...

https://en.wikipedia.org/wiki/Wormhole