The fate of the universe is a topic of ongoing scientific research and speculation. While there are different theories about the ultimate fate of the universe, I'll mention two possibilities that have been proposed.
Heat Death: According to the prevailing theory known as the heat death scenario, if the universe continues to expand indefinitely and the amount of usable energy gradually declines, it could eventually reach a state of thermodynamic equilibrium. In this scenario, all the stars would burn out, and all matter would decay or disperse. The universe would become cold, dark, and devoid of usable energy. However, even in this state, the universe would still exist, albeit in a vastly different form.
Big Crunch or Big Bounce: Another possibility is that the expansion of the universe could reverse due to gravitational forces, leading to a contraction known as the "Big Crunch." In this scenario, the universe would collapse in on itself, potentially resulting in the formation of a new singularity or a "bounce" that triggers the birth of a new universe.
It's important to note that our current understanding of the universe is incomplete, and these theories are subject to revision and refinement as new observations and discoveries are made. The ultimate fate of the universe is still an active area of scientific investigation and speculation.