What are you talking about? "Dark Matter" and "Dark Energy" are terms used to describe to _obeserved_ phenomona that we can not explain. And I'm not even sure what a "hypothetical" variable is.

They have observed discrepencies in the calculations, meaning something is either wrong with the formula, or something unobservable actually does exist and manipulates the universe in such an (edit: so far) unexplainable way.