Turns out that the dynamical equilibrium model is wrong, though. This is a very old model that had to be abandoned because it could not explain the CMB. More recent data like the time delated decay curves of distant supernovae confirms that the red-shift cannot be explained that way. Moreover, the evidence for dark matter has build up to a level that it is not unreasonable to characterise it as extremely likely.
Edited by fallacycop, : Some typos and clarifications