Well, it has a gravitational effect, so it definitely exists inside of our normal spacetime.
Scientists have explored alternative models of gravity or spacetime with additional spatial dimensions and things like that. As far as I know, none of them are very promising. There was an interesting PBS space time video about one example recently: https://youtu.be/3HYw6vPR9qU
Of course, it is definitely interesting to think about :)
I guess for me the analogy is to the sphere in flatland being perceived as a circle - we can see evidence of dark matter but so far we can’t really detect or measure it directly. I wonder if the gravitational effect is the only clue that we’ll find inside “normal” spacetime.
The most exciting thing about that is the idea that the hunt for dark matter might eventually lead to an understanding of the “rest of the universe” where we would otherwise never have a hint of its existence.
Scientists have explored alternative models of gravity or spacetime with additional spatial dimensions and things like that. As far as I know, none of them are very promising. There was an interesting PBS space time video about one example recently: https://youtu.be/3HYw6vPR9qU
Of course, it is definitely interesting to think about :)