A Jewel at the Heart of Quantum Physics
I have no way to evaluate this. This could be overselling a new idea or they could be onto something. If there’s a geometric way of expressing scattering probabilities, great. I suppose it’s possible to view Feynman diagrams as expansion terms of some function, so if they’ve found a way to figure out the underlying function, that’s wonderful. Amplituhedron seems a tad cute, but then I’m in a sub-field where someone made up Bosenova, so atomic physics doesn’t exactly have the high moral ground here.
One thing that gives me pause is any claim that they have discovered any “true” nature of anything. Like all of physics, we are talking about models. Physics describes how nature behaves, not what it really is.
Looks like overselling a new idea, to me. You’re right that this basically looks like a clever way to add up terms of the perturbation series, and so far only applies to Super Yang Mills. The proposers of the theory say that expanding this result to real theories is a known quantity, but I’d bet that such an expansion is likely to break a symmetry critical to the simplification they’re seeing.
I also do not yet see a justification for how this advance leads to their claim that unitarity and locality are both out the window.
The amazing thing with twistor string theory is that you can deal with an infinite number of certain classes of Feynman diagrams found in Yang-Mills theories. The work you link to is probably a bit of an over-sell, but they have added something to this understanding. It is a little far from my area of expertise to really judge this.