Wikipedia says:
It is believed that, due to the extraordinarily small scale of the universe at the time, quantum effects of gravity dominated physical interactions.
But I wonder whether there is any indication that the dimensions of the universe were small at the time rather than being infinite?
Undoubtedly it was very dense but very dense does not necessary mean "small".
Is Wikipedia wrong on this point?
If the universe is infinite now, it must also have been infinite during it's earliest phase greater than t=0. If the universe is finite now, it it must also have been finite during it's earliest phase greater than t=0. What happens at t=0 is undefined since the GR equations for the universe have a singularity at t=0.
One of the comments mentioned the finite "visual" universe, also more commonly called the observable universe. This is always finite independently of whether the (whole) universe is finite or infinite.
Sometimes you may see in an article the term "universe" (carelessly) used when the intended meaning is "observable universe".
