[c048]

That's the thing about time-loops; you don't need to have a start and a beginning. There's a good movie about that concept; Interstellar.

[Tenoke]

Interstellar is pretty much nonsense even given the premise. Even if you are talking about time travel you can easily make something more plasuible than that.

Also Interstellar had information passing from the future to the past which isn't really what's typically sufficent to consider it a time loop.

[westcort]

The time loop is allowed by the current understanding of physics. The math checks out.

[ben_w]

Interstellar has one, but for that topic I'd suggest Predestination: https://en.wikipedia.org/wiki/Predestination_(film)

I'd also suggest watching it before reading that plot synopsis.