when they are BOTH hypotheses that explain phenomena in the universe that we cannot explain by our current understanding (and there ARE other hypotheses that explain them)
(for those who dont understand what a hypothesis is I suggest getting a dictionary - its no better than an educated guess)
Both of these have been assumed to have properties in order to explain the phenomena, but so far there is NO actual evidence that either exists.
And just cos in so many scientists "opinion" they exist does not make them fact
The ONLY facts we have are that the phenomena exist.
The only explanations we have are hypotheses (educated guesses) NOT facts.
Maybe in time they will become fact but at THIS time they aint