Dark matter is a supersolid that fills 'empty' space and is displaced by ordinary matter.
The supersolid dark matter displaced by a galaxy pushes back, causing the stars in the outer arms of the galaxy to orbit the galactic center at the rate in which they do.
Displaced dark matter is curved spacetime. More correctly, what is referred to geometrically as curved spacetime physically exists as displaced dark matter. Curved spacetime is a geometrical representation of gravity. Displaced supersolid dark matter is the physical manifestation of gravity.
The supersolid dark matter displaced by the quarks the Earth consists of, pushing back and exerting pressure toward the Earth, is gravity.
Displaced supersolid dark matter is gravity.
The reason for the mistaken notion the galaxies are missing dark matter is that the galaxies are so diffuse that they don’t displace the supersolid dark matter outward and away from it to the degree that the dark matter is able to push back and cause the stars far away from the galactic center to speed up. The galaxies are too diffuse to displace the supersolid dark matter to such an extent that it causes the light to lense as it passes through the galaxies.