This theory requires the 'dark matter' to be in its superfluid phase in galaxies, but in a different phase outside. Also, an important difference between dark

This theory requires the 'dark matter' to be in its superfluid phase in galaxies, but in a different phase outside. Also, an important difference between dark matter and empty space is that the expansion of the universe doesn't generate more dark matter but does generate more space. This is what distinguishes dark matter from dark energy.