What does the BGV theorem say?

[Rumraket (Mikkel R.)]

@Jim

These quotes are attributed to Vilenkin:
“It is said that an argument is what convinces reasonable men and a proof is what it takes to convince even an unreasonable man. With the proof now in place, cosmologists can no longer hide behind the possibility of a past-eternal universe. There is no escape: they have to face the problem of a cosmic beginning.”

“There are no models at this time that provide a satisfactory model for a universe without a beginning.”

“All the evidence we have says that the universe had a beginning.”

“The answer to the question, “Did the universe have a beginning?” is, “It probably did.” We have no viable models of an eternal universe. The BGV theorem gives us reason to believe that such models simply cannot be constructed.”

It seems he’s at least convinced that there is a beginning. Doesn’t the BGV theory suggest a singularity regardless of GR or QT? That seems to suggest a beginning is highly probable, doesn’t it?

What does Vilenkin mean by a beginning? Does he mean the universe at first did not exist at all and nothing did, and then later it suddenly existed?

Or does he simply mean that the universe has a finite age, and thus a first “moment”, or instance, on the axis of time?