What will the GR become in higher and lower demetions?
In the book Planiverse ,the author told us that the GR can't work in 2D space because it can't contain any gravity.
I'm interested in that and I want to know more about that.
So,what will the GR become in 4D and 2D?
Please show me sth. about that.
P.S. Please forgive my grammar and spelling mistakes,I'm not good at English.