“Not insofar as particle plus anti particle equals energy.”
Perhaps for conventional particles, but not for virtual particles. There is no net gain of energy when virtual particle pairs annihilate.
“But if on occasion those particles remain separated, with half the pair randomly sequestered in a black hole or some such, there will remain a practical net positive (albeit small) that can float about space, attract, and eventually aggregate into large orbs; this of course would take a long time.”
There is still no net increase in matter, whether they are separated or not. There is still an antiparticle and a particle in existence in the universe, which cancel each other out when we are speaking of the total amount of matter in the universe.
To demonstrate mathematically, the universe before the virtual particles are produced is represented by this equation:
M = X
where M is the total mass and energy of the universe, and X is that unknown total amount.
After the creation of a virtual particle pair, the equation would be:
M = X + a - a
where a is the mass and energy contained in one of the virtual particles. Whether the particles annihilate or not, that equation still reduces to:
M = X
Which is identical to the original equation. The total mass and energy (M) never changes.
“which cancel each other out when we are speaking of the total amount of matter in the universe.”
Ok, so there’s a grand total of zero in the universe. That doesn’t conflict with there being a bunch of particles over here aggregating into something we call Earth, while a bunch of anti particles are over there stuck in a black hole or some such.