Imagine space but completely empty except for virtual particles popping into and out of existence.
Now place into that space two black holes separated by some distance.
The black holes would begin to emit Hawking radiation. Now as I understand Hawking radiation is a process by which virtual particles are converted it into real ones.
Imagine one of the black holes emits a real particle via Hawking radiation that travels through space and gets absorbed by the other black hole.
Would that be a force that tends to push the two black holes apart? Are the particles emitted by black holes in some sense bosons?