Assuming the validity of 
Assuming the validity of the lambda-CDM model, in which dark matter is exclusively slow and non-baryonic, this quantity is calculable from observing the associated microwave shifts in the Sunyaev-Zeldovich effect. The square of its time-dependent form is related to the time derivative of the scale factor over the scale factor in one of the Friedmann solutions to Einstein's field equations. The current value for this constant was obtained from the WMAP mission's study of the cosmic microwave background. For 10 points, identify this quantity estimated at 71 kilometers per second per megaparsec, whose reciprocal approximates the age of the universe.
Assuming the validity of the lambda-CDM model, in which dark matter is exclusively slow and non-baryonic, this quantity is calculable from observing the associated microwave shifts in the Sunyaev-Zeldovich effect.
{Hubble} constant or parameter