Fred:

Of course they also state:

“Although the Copernican principle may be widely accepted by fiat, it is imperative that such a foundational principle be proven,” Caldwell and Stebbins assert in an upcoming Physical Review Letters. The researchers suggest a concrete way to check once and for all whether our neck of the cosmic woods is different from other parts of the universe. Their test relies on observations of the cosmic microwave background, the leftover radiation from the Big Bang that bathes all parts of the universe.

Thus what they are "really" saying is that once again we have a "tacit" assumption that should, and can, be made subject to experimental verification or falsification!

This is also to say nothing of there being at least some evidence that the Universe is not accelerating, and, hence, there need be no "dark energy".

David

P.S. You used the term "dark matter" in the body of your post where you should have used "dark energy". I trust this was simply a tiny lapse. :-)

P.P.S What?!? Now Blockquotes do nothing?!?