Then what is accelerating the source of the acceleration? OMG, it's turtles all the way down!! 
It is a two-way force. The upward portion is accelerating the matter above it, and the downward portion accelerates the DE itself.
So the DE/UA pushes the earth and pulls its source along for the ride?

How could that possibly work? Again, Newton's third law - action/reaction. If the UA is pushing against the FE at one end, it has to push against something else at the other end. That is, unless Newton was wrong about that too.