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Can anyone point me into the right direction on how to come out with a value/ expression for the density parameter of aradiation dominateduniverse.

Things that I know of/ can recall are:

Friedmann equation :

[tex] 8/3 \pi G ρ R^2 -kc^2 [/tex]

Also when radiation dominates matter then we get ρ = 1/R^4 ( I think)

Density parameter :

So what am I missing to give me the density parameter ? [itex]\Omega_{m}[/itex] = [itex]\rho / \rho_{critical}[/itex]

where

[itex]\rho_{critical}= (3H^2 q / 4Pi G) [/itex]

Any sort of help is appreciated.

-ibysaiyan

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# Density Parameter for radiation dominated universe

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