see: https://phys.org/news/2022-05-universe-collapse-dark-energy-quintessence.html
A trio of astrophysicists, two from Princeton, the other from New York University,
has calculated estimations on how soon the universe could collapse if theories regarding
dark energy as having quintessence are correct.
The book of Stephan Denaerde seems to be right that the universe (we) end into an other dimension. However is seems to be not very dangerous.
see: Het is een onleesbaar boek, zegt dit verslag met een uitstervend einde. (Big Crunch)
However, in Q-FFF Theory it seems logic for a pulsating or cyclic universe.
The Pyrochlore vacuum structure as supported by Q-FFF Theory: called Pyrochlore crystal structure with fluxtube lattices with variable length (lightspeed) and 6x directions in space.