fyi
I have had this conjecture for a number of years:
Suppose the Universe is not expanding at an accelerating rate. Suppose it it in reality, a giant black hole and everything is collapsing to its center.
Consider the usual model of a black hole as a rubber sheet pulled down into a space-time “cone.”
Any object at any point on this cone, eg, the earth, when looking at any other object, sees an object that is
a. Further “down” the cone,
b. “Higher up” the cone,
c. At a same axial “circle of latitude.”
Therefore, if the object is further “down” the cone, it will be travelling faster than us and appear to be moving away at an accelerating rate.
Any object “higher up” the cone will be travelling slower than us and therefore it will also appear to be moving away at an accelerating rate.
An object on the same “circle of latitude” will probably appear to be approaching us, assuming that a geodesic from us to that object would be the “circle.” But such objects would be rare cosmologically.
Perhaps “dark matter” or “the great attractor” could be attributed somehow to the gravitational attraction towards the “center” of the black hole itself.
I don’t have the math or the physics knowledge to try to prove or disprove this conjecture. But it has haunted me for a long time.