I have a theory regarding gravity. I don't have the math to prove or disprove it and am too lazy and/or dumb to acquire it. It may not be a new theory but I've never heard or read about it.
Here goes. We know the universe is expanding and maybe accelerating. We look and see a doppler red shift in every direction. The farther we look the greater the shift.
Imagine there is another dimension coexisting within every point of ours. I think String Theory is up to 12 dimensions now. This part of the theory is not mine. However, these other dimensions are tied to ours in some manner at the sub atomic level, at every point in space. Maybe the specific strings which make up our universe also make up other universes and so it is those "strings" that create the bond. Part of the string vibrates in a pattern that makes it part of our universe and another part of the same string vibrates in a pattern that is not part of our universe but is part of another. The areas of space with more densely populated strings are known as energy/matter, mass.
Back to the expansion of space. It is expanding. That doesn't mean that objects are just moving farther apart through empty space but rather that space itself is expanding. Again, this part is not my theory but is accepted as evidenced. My theory is that space becomes stretched by mass because mass is anchored to another dimension. This stretching created by the expansion is why mass warps space.
Half baked theory I know.