There are some cosmological theories that suggest that the universe as we know it could be infinite, meaning that it has no beginning or end. One possible approach to understanding an infinite universe is mathematics, in which some theories suggest that the universe may be a spatially infinite but temporally finite model expanding from a singularity. Another possible approach to an infinite universe is considering various models such as "cyclic" or "eternal recurrence" models of the universe that have been suggested in cosmology. Ultimately, the question of whether the universe is infinite or not, as well as whether it has existed eternally or emerged from some kind of beginning, is a subject of ongoing scientific and philosophical inquiry, and there are many different theories and perspectives on this topic.