What caused the Big Bang is dark energy, a strange energy expanding the universe, that's why I chose it.
For dark matter my theory was that as E=mc2, the dark energy can be converted into dark matter.
For the properties of dark matter of it being like a ghost(it can pass right through anything).
Dark matter could have an atom that is different from others that might be smaller, small enough to pass through your body.
Dark matter and energy is basically matter and energy that is ample in the universe that doesn't interact with light making it hard to detect, so it is why the universe looks dark but is transparent.
The reason for dark energy being the cause of the big bang is that, 1, it is one type of energy, 2, it expands the universe, which makes it likely that it expanded the singularity to cause it and 3, it still continues to expand the universe from the start.
Dark matter, as I said, could be a type of matter that has a atom which has different properties, like anti-matter.It could have originated from dark energy as E=mc2, so it is one of the possible origins.
For the origins of dark energy, it is the energy in the singularity that expanded the universe into existence with it's contents.
For the equation is,
(Dm=Dark matter, De=Dark energy)
expansion of space=De=Dmc2