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## Homework Statement

the first friedmann equation is:

([itex]\frac{\dot{a}}{a})^2[/itex]=[itex]\frac{8\pi G\rho}{3}[/itex]-[itex]\frac{kc^2}{a^2}[/itex]+[itex]\frac{\Lambda}{3}[/itex]

In the case of a closed Universe (k > 0) containing only non-relativistic matter and no cosmological constant, write the Friedmann equation in terms of, H(a), H

_{0}, a and Ω

_{0}(where Ω

_{0}is the current matter density parameter). Assume that the current scale factor, a

_{0}= 1

## Homework Equations

## The Attempt at a Solution

so far what I have is:

H(a)

^{2}=H

_{0}

^{2}Ω

_{0}-[itex]\frac{kc^2}{a^2}[/itex]+[itex]\frac{\Lambda}{3}[/itex]

I've seen things like

H(a)

^{2}=H

_{0}

^{2}[[itex]\Omega_0\frac{a}{a_0}[/itex]+1-[itex]\Omega_0[/itex]]

but I have no explanation for this and so can't tell if it's right.