While I have no evidence, I believe the notion of duality is an illusion created due to the observers point of vantage being confined within our spacetime.
Consider a superluminal particle moving through a spacetime with 3 time dimensions and one spacial dimension. Does this mean if we apply the equivalence of a Heisenberg uncertainty principle in the mix, it becomes difficult to know when a particle is? What does mass do in a single spatial dimension if it has 3 temporal dimensions to jiggle in?
After thinking about all that just a bit, is it possible that a single gravity well can produce a gravity field in multiple (possibly adjacent) time domains? Is dark matter really normal matter which is actually there, just not yet/then/now?