t claims to eliminate locality/unitarity seems decidedly odd to my mostly-untrained mind.
The article is confusing on this point. IIUC, the amplituhedron does not eliminate either unitarity or locality. What it does is to avoid taking them as axioms, as the Feynman approach does. Then it later turns out that they fall naturally out of the math, which is much nicer.
I figured as much. That still seems mildly odd, but that’s probably because I’m used to thinking of them as axiom-ish principles and not as derivative results.
FWIW I’ve seen the same thing said by other people elsewhere, though of course it’s possible that they and the HN comments derive from a common source. Also, my understanding is that the amplituhedron approach produces the exact same numbers as enumerating Feynman diagrams does, just quicker and in something more like a closed form, so it has to be as local and unitary as any other way of doing QFT.
The article is confusing on this point. IIUC, the amplituhedron does not eliminate either unitarity or locality. What it does is to avoid taking them as axioms, as the Feynman approach does. Then it later turns out that they fall naturally out of the math, which is much nicer.
I figured as much. That still seems mildly odd, but that’s probably because I’m used to thinking of them as axiom-ish principles and not as derivative results.
Where did you get that from? Did you read the primary, or is there some actually decent exposition of this somewhere?
Comments on HN. Sorry! But I read it on the Internet, so it must be true.
FWIW I’ve seen the same thing said by other people elsewhere, though of course it’s possible that they and the HN comments derive from a common source. Also, my understanding is that the amplituhedron approach produces the exact same numbers as enumerating Feynman diagrams does, just quicker and in something more like a closed form, so it has to be as local and unitary as any other way of doing QFT.
You can watch/listen to Arkani-Hamed’s recent talk at SUSY 2013. At around 2:00, he says:
At around 6:00, a written slide describes his strategy:
He goes on to discuss this subject in more detail.
Also, (somewhat technical) slides from his former student have a section called “Emergent Locality and Unitarity”.