The most accepted model of the universe needs Dark Energy and Dark Matter to work. It needs this Dark stuff to the tune of 80%. This stuff has not been observed and the properties are unknown. Now there is a new model that does not need it. http://www.universetoday.com/98864/do-we-really-need-dark-matter/ Will this one win out in the end? Is that not how science work? We find a way to describe how something work by observing what is happening. Seems to me that if you base a model on only 20% of known data it is not a strong model. Maybe Mefiante can look at this and share her thoughts?
As long as they leave dark chocolate alone. My universe will promptly stop working without dark chocolate. 
R.
Ah Cosmology when they don’t understand it they put the word Dark in front of it. Sounds better than Mystery Energy