Radiation in universe

[wolram]

(if) our universe is closed and finite, would it become (soaked) in radiation
more readilly than an open infinite universe?

[SpaceTiger]

(if) our universe is closed and finite, would it become (soaked) in radiation
more readilly than an open infinite universe?

I don't think so, but one might naively expect an ordinary unity change in the radiation density in a finite universe with a small topological scale. If we were to see multiple images of objects, then clearly the simple 1/r^2 dilution wouldn't apply anymore.

Also, a closed universe without dark energy would eventually lead to a contracting phase, near the end of which the universe would become radiation-dominated.