Or in this case
Dark matter is only one *possible* explanation, MOND/MiHsC, entropic gravity, entanglement wormhole cascade, the list goes on and on.
In fact, I came up with a variant this morning, perhaps the "missing" matter in the Universe is entangled antimatter, exerting a weak negative (ie repulsive) gravity on empty space.
The sheer amounts involved are staggering, also explains the 511keV spikes.
(see new paper to be released around April)
In related news, was "The Word", KABOOM? Film at 11.