Is there an end to the universe?
There are more than a couple ideas of how the universe will end.
One is the rate at which the universe expands will increase to the point where even the space between the atoms get stretched thus ripping them apart overcoming the strong force holding them together. The universe will continue to expand but there will be no matter, no stars, nothing because no particles will be able to form due to this rate of expansion.
Another idea is that the rate of expansion will either have a limit or threshold by which it will either stop accelerating or some other force will slow it down or even reverse it. If it reverses the universe will collapse back in on itself.
My favorite idea is one where all the matter that makes up the universe will re-condense back into a singularity. There is evidence to support this idea which is the galactic filaments showing how galaxies are being brought together into clumps. As their gravitational influences increase given enough time galaxies will collide and in turn increase their gravitational influence dragging in more galaxies until you have just a few hundred billion super massive galaxies which will in turn again be brought together to ultimately recreate the singularity. This is the recycled universe idea. It's possible that this cycle has occurred unending if it is true.