Of course, this question runs perilously close to this site's prohibition against discussing non-mainstream physics. However, the accepted answer in meta about what is acceptable and what is not acceptable regarding non-mainstream physics, says that it's okay to ask for an evaluation within mainstream physics of a new concept or paradigm. I believe my question falls under this heading. The new concept is that it might be possible (counter-intuitively) to accelerate a body in a vaccuum without a traditional propellant. My understanding from this article (paragraph starting "Dr. White proposed") is that the engineers at NASA have some kind of theory which is supposed to fit into mainstream physics about how this would work. But I'll understand if people vote to close.
The article I've linked to is not technical, and provides no technical references. My Google-fu has not managed to uncover a more technical description anywhere (I can't even find a homepage for the group doing this research). So
Question: What exactly is the theoretical mechanism that NASA (in particular, Sonny White, in particular, not Roger Shawyer) is proposing? And where can I read about it?
The proposal is apparently precise enough to build a computer simulation off of it (see near the end of the article, the section labeled "Progress Update"), so I'm assuming that it must be intelligible.
For example, here's something that might be the sort of thing they're talking about. Imagine that on your spacecraft you have a gamma-gamma collider (powered by a nuclear reactor or solar panels or whatever). When the photons collide, they create lots of high-energy electron-positron pairs spraying out in all directions. By clever design of the hull of your spacecraft, let's say that you preferentially readsorb electrons / positrons moving toward the bow of the ship (e.g. put a big lead block to the bow of the collider). Then you will generate momentum going forward. Your propellant particles have been bought from the vaccuum.
Now, the EM fields involved in the NASA setup are nowhere near this strong, so the mechanism can't be quite this. The article I linked to says something about virtual particle-antiparticle pairs, so maybe the proposal is that the "propellant" is made up of waves in the electron field which are not localized as particles?
EDIT Earlier questions have focused on whether the proposed effect would violate conservation of momentum. My assumption is that if we actually look at NASA's proposed mechanism, we will see that it's not violating conservation of momentum, just sending that momentum off into "new" particles, as in the example version I sketched. I'm really mostly interested in seeing the actual proposal, so maybe this question is best viewed as a reference request.
EDIT I'm disappointed to see this question marked as a duplicate. I'm asking for a specific link, and I haven't seen that link, nor have I seen a definitive claim that the link I'm looking for doesn't exist.