Physics Speculation – Two Object Gravity?

A quick idea.

I wonder. Could Newtons gravity law give inspiration to another form of gravity. I mean. It describes the force between two objects. So what if one object is another type of object. Like a empty space object.

Then does there exist Empty Space Gravitation?

I recall the universe is expanding. Since something that is almost empty is a lot easier to expand. Then could empty space expansion and gravity between mass and the empty space object explain this expansion?