The concept of exotic charged dust is introduced here to represent dark matter. The term “exotic” means that the dust is not composed of normal matter, and the charge-for lack of a better term-is not an electric charge. It is also shown that the often-used approximate
expression for dark matter density corresponds to an exact solution of the coupled Einstein-Maxwell equations for charged dust. The Einstein field equations tells us is that for a flat universe the cosmological constant acts as a gravitating negative energy distribution that is gravitationally repulsive; following Schwinger, it is shown that the vacuum must have a negative energy spectrum if QFT is to be gauge invariant.
http://arxiv.org/abs/2406.15461