Radiation in a Closed/Finite Universe?

AI Thread Summary
In a closed and finite universe, the expectation of increased radiation density compared to an open infinite universe is debated. The simple dilution effect of 1/r^2 may not apply if multiple images of objects are observed. A closed universe without dark energy is predicted to enter a contracting phase, ultimately becoming radiation-dominated. This suggests that the dynamics of radiation in a closed universe differ significantly from those in an open universe. Understanding these differences is crucial for cosmological theories regarding the universe's fate.
wolram
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(if) our universe is closed and finite, would it become (soaked) in radiation
more readilly than an open infinite universe?
 
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wolram said:
(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.
 

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