I mean in the amount of energy it has and in its size. That which is observable is apparently only a sub-universe. It seems to be limited only by physical laws, but even those laws could be different in other sub-universes.
I don't know about any differences. Particle physicists don't have much of an opinion on gravity and on uniting gravity with the other forces.
A proton and neutron can still have three quarks each with some of them being matter quarks and others being antimatter quarks. The strong and weak forces can be manifestations of gravity and electromagnetism at short scales, and electromagnetism could be a manifestation of gravity and anti-gravity, but particle physicists generally do not concern themselves with such ideas.
Now that I think of it, the conventional gravity lens is the convex lens, so the negative lens supposedly created by Hoag's ring and center-spot should be concave. That is also the way I described it about a year ago.
What I hypothesized back then was the two complementary lensing actions have an effect similar to a achromatic doublet, and so the red Einstein ring is basically the same color as the red lensing object in the middle of the Einstein ring that forms the ring, whereas typically the ring color is bluer.
It seems there are some comparatively smaller objects right in front of the red Einstein ring and these objects disrupt the ring image portions nearby, which gives each of these objects, visually superimposed over the Einstein ring, a tiny dark halo.