According to the Many Worlds interpretation of quantum physics, all the possible universes coexist at the same time. Essentially, every time atoms interact in ways where there is more than one possible outcome, universe splits into separate universes where all the possible outcomes have happened. The Schrödinger's Cat is dead in one, alive in another and has turned into a dog in third. There is innumerable amount of these other universes in different “frequencies” but we cannot interact with them.
(Yes, this is a gold mine for New Age practitioners, postmodernists and parapsychologists and quantum physicists should not
be dismayed that they are summoned to media events alongside with proponents of those views – they
originated the idea!)
Now, universe seems to be filled with what astronomers call Dark Matter and Dark Energy. Dark Matter is something astronomers cannot directly observe but, among other things, without it the galaxies would disintegrate due to weak of gravity. Dark Energy is also something astronomers cannot directly observe but it keeps the universe expanding. Scientists can observe both only indirectly by seeing their effect on the universe.
(Personally, I think that both dark energy and dark matter may go the way of the Luminiferous Aether as soon as someone develops a new equivalent to the theories of Einstein that made things like Aether unnecessary assumptions)
Now, both quantum physicists (especially those who believe that conscious mind is somehow necessary for matter to exist) and cosmologist will probably ridicule me for this but so what:
If we coexist with innumerable universes caused be all the possible outcomes in particle interaction ever since the Big Bang, that means that those universes multiply in number every time something happens. Even quantum theories about virtual particles postulate that sometimes they do not obliterate each other (according to Hawking, this means that Black Holes will eventually evaporate when their mass does not increase any more and we see the effect as radiation). Still, we cannot interact with those other universes or observe them.
According to thermodynamics, one cannot totally destroy matter or energy, just convert them into another form. Physicists have long tried to integrate gravity into Grant Unified Theory but gravity is very hard to monitor and observe.
Does the multiplying matter and energy from the other universes affect gravity in large scale? Is there so much of it that the net effect creates the gravitational effect the astronomers see as effect of Dark Matter and pushes the universe in velocities they see as effects of Dark Energy?
Now, the next words any physicist will say probably include phrases like “it's not like that”, “It's not that simple”, “You don't understand it at all” (to their credit, most quantum physicists admit that they don't really understand the theory they use in their everyday equations) and “You just don't get it” (the ultimate statement of dogma, especially in the arts).
If not, the question is; where all that mass and energy from those extra universes go?