Much time later, the expansion seems to neither accelerate or decelerate, as the universe keeps expanding at a steady rate. Eventually, the temperature goes down as the density of the concentration of galaxies also goes down. At the temperature close to zero, things dissolve into subatomic particles.
This is only the scenario which doesn't lead to new gravitational singularities.
- Big Bang - The event starting the formation of an universe
- Big Bounce - Universe ending scenario, where a new one starts right after
- Big Crunch - Universe ending scenario, reversing the expansion rate until a gravitational singularity
- Big Rip - Universe ending scenario, accelerating the expansion into infinity