If you want to constantly simulate a larger universe in places unobserved to the user, no you can't, in real time. If you slow down the simulation by many many orders of magnitude and use a quantum computer, you may be able to pull it off, but it just isn't worth it.

If you want the simulation to only be computed at high resolution near the user (and low resolution at long distances), yes you can give the illusion of a more vivid and larger universe.