Friedman Equation
•Homogeneous and Isotropic universe is described geometrically by a metric, or line element, in GR, for “pressureless dust”. •Einstein field equations yield the Friedman Equation (no cosmological constant):
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•Term on left is Hubble parameter: or            H = 1/R(dR/dt), and k is the curvature term from the R-W metric (-1,0, or +1)