- #1

QuarkDecay

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- TL;DR Summary
- FRW Models and densities

Can we say that a universe with a radiation density (only) exists only in near a Big Bang time, and not a Big Crunch? Since it gets much smaller as time passes.

For example in here:

http://www.nat.vu.nl/~wimu/Varying-Constants-Pictures/Time-Scale-Universe.jpg

We have different cosmological models for different times. But what about their densities?

For example, in the closed Universe with k=+1 and without a cosmological constant. Can we say that at Big Bang we only have the radiation density, but in the Big Crunch only the matter density?

For example in here:

http://www.nat.vu.nl/~wimu/Varying-Constants-Pictures/Time-Scale-Universe.jpg

We have different cosmological models for different times. But what about their densities?

For example, in the closed Universe with k=+1 and without a cosmological constant. Can we say that at Big Bang we only have the radiation density, but in the Big Crunch only the matter density?