I was reading an article about precise measurements for the scale of the galaxy, and it got me thinking.
The article suggests that the universe is flat and composed of just 4% matter.
From observations the universe is composed of filaments along which the galaxies thread their way.
So what if....
You imagine these filaments we laid out on a flat surface like a piece of paper. so now imagine a piece of A4 paper.
Dark matter and dark energy are then pasted onto the top and bottom surfaces of that piece of paper like papermache.
You then crumple the paper into a ball.
The universe we observe is still only the thin sheet of A4 paper that runs through the ball of paper, and that is all we can see.
Dark matter and dark energy still make up most of the paper ball but are actually OUTSIDE our observable universe (the sheet of A4). But because they are crumpled together between the folds of the observable universe they are part of it and ouside of it at the same time.
So does dark matter and dark energy exist at 90 degrees to the observable universe.
I am sure that some boffin somewhere has considered this option and worked on it, at the very least I would hope so.