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Particle physicists puzzle over a new duality
- ISL 4y agoVery pleased to see news like this -- observations of this sort are where the big theoretical advances sometimes emerge.
- jobs_throwaway 4y agoIndeed, this is the sort of stupefying discovery that hints at something deeper
- cwillu 4y ago“For Dixon, this is a tiny hint at a deeper physical connection between the two amplitudes, and a reason to think something similar might hold in the Standard Model. “But it’s pretty weak,” he said. “It’s, like, secondhand information.”” This appears to be a development in a toy model. It might or might not apply to the standard model. Still, at least it isn't a condensed matter experiment being misconstrued as a particle physics breakthrough.
- phkahler 4y ago>> misconstrued as a particle physics breakthrough Hey don't throw shade on quasiparticles, they're people too.
- cwillu 4y ago“I identify as Higgs”
- davrosthedalek 4y agoQueue "yo mamma" joke.
- zmgsabst 4y agoWhen does a quasiparticle become “particle physics”? As far as I can tell, protons and neutrons are quark-gluon quasiparticles, but we’re happy to call studying protons and neutrons “particle physics”. From Wiki: > complicated system such as a solid behaves as if it contained different weakly interacting particles in vacuum That is, this description fits protons and neutrons relative to quarks and gluons: very cold quark-gluon regions behave as if protons and neutrons exist. https://en.wikipedia.org/wiki/Quasiparticle https://en.wikipedia.org/wiki/Quasiparticle
- roywiggins 4y agoQuasiparticles, as usually defined, are embedded in some bulk substrate. So electron holes exist as part of a chunk of metal, for example. Phonons are mechanical vibrations of some bulk matter. They're not made of any particular piece of the bulk matter, like a molecule is made of atoms or a proton is made of quarks; they're emergent phenomena (an electron hole is "made of" not an electron- it's only a hole because of the matter surrounding it)., Protons and neutrons, on the other hand, exist in free space. You can accelerate protons and fire them at the moon (or whatever). You can't do that with phonons or electron holes. They are composite particles (not fundamental) but they aren't quasiparticles. (quarks, weirdly, can't exist in free space. If you try to pull a proton apart you will have to put so much energy into it that you generate more quarks which then immediately couple up with the proton's quarks, possibly in a novel combination producing new composite particles. So you have to study composite particles to study quarks)
- zmgsabst 4y agoI’m unaware of any “free space” which doesn’t have a mass of quarks and gluons oscillating, so I’m not sure I follow. In fact, the mass of the proton arises from disrupting that typical quark-gluon oscillation. I’m also unsure that’s true, even ignoring that issue: I can shoot an electron hole by moving the chunk of metal it’s situated in, the same way I can shoot a proton by shooting the constituent quarks and gluons. You can’t separate an electron hole from the metal, but you also can’t separate the proton from quarks and gluons.
- joe__f 4y agoI finished up my PhD in scattering amplitudes recently. I checked out the abstract of this paper, and it certainly looks like an interesting result and will likely be the basis for new results in the field. For perspective, I estimate that there are a few such results in the field per year which could have roughly the same quanta magazine article written about them.
- mmazing 4y agoAny guesses what this could stem from?
- joe__f 4y agoI think it's a bit of a feature of quanta magazine's approach to science journalism (and probably the current zeitgeist in science journalism in general). If you want to make work like this accessible then it's necessary for a large portion of the (pop science) article to be covering topics that are common to most of the recent work in the field, with a lot of the same analogies and motivations. I think it's nice that quanta magazine are trying to make this kind of work accessible and interesting for people, but I feel that their approach sacrifices perspective on how relevant that work is, which is why I tried to add some here.
- ravi-delia 4y agoI agree with everything here, but suspect the person you replied to was asking what caused the strange correspondence :P (or, even if they weren't, I'd like to ask for myself)
- joe__f 4y agoI'm happy to answer your question, but I'm not sure what you're asking
- mmazing 4y agoThanks for the response, but I was mostly asking about your experience as someone working in this particular field. Do you have any guesses for what might be the connection between these two different scattering amplitudes in seemingly disconnected physical phenomenon?
- nottim 4y agoThe first sentence of the abstract is a helluva mouthful: "We observe that the three-gluon form factor of the chiral part of the stress-tensor multiplet in planar N = 4 super-Yang-Mills theory is dual to the six-gluon MHV amplitude on its parity preserving surface." For any of you paper-writers out there, some advice: the abstract shouldn't contain undefined acronyms, and should be readable by anyone who you would expect to be at a conference where you present your paper. Exchanging a bit of the technical correctness for readability is the entire point of the abstract, and the source paper's abstract could really use some work.
- raverbashing 4y ago> and should be readable by anyone who you would expect to be at a conference where you present your paper. Yes, I guess this is pretty much the case here. There's no much way to simplify this Conciseness is important in abstracts and it beats general simplifications.
- ISL 4y agoThat sentence is very readable for anyone who would be at a relevant conference. As an experimental physicist, everything but the MHV (maximally helicity violating) was readable/comprehensible to me. Theorists in the field will read that as easily as breathing.
- sebastialonso 4y agoContext is king. It's the abstract of a paper, not simple Wikipedia. Everyone reading the paper itself is expected to either know or make the effort the become knowledgeable enough to understand. In any other context, I'd agree but we're taking about a paper on theoretical physics on a potential new interaction lol
- galaxyLogic 4y agoI think this would be a great task (and challenge) for AI: Make abstracts understandable to a wider audience.
- mannykannot 4y ago
- gfodor 4y agoCan a physicist comment on the impact of this to the work by Nima Arkani-Hamed et al on the Amplituhedron (https://en.wikipedia.org/wiki/Amplituhedron https://en.wikipedia.org/wiki/Amplituhedron)?
- joe__f 4y agoGreat question! This result is in the same area as the work on the amplituhedron. It's not immediately obvious to me that they are directly related, and I didn't see a reference to any amplituhedron papers in the citations of this paper. Dixon et al. have essentially discovered a new symmetry which the scattering amplitudes (of N=4 Super Yang-Mills) must obey, and new symmetries generally lead to deeper understanding of the theory. This symmetry should then also be somehow encoded in the amplituhedron description of the theory; I imagine people would look into this in the future.
- gfodor 4y agoCool, thanks!
- legohead 4y agoAs a complete layman to all this, after reading the article it feels like more proof we are in a simulation.
- uoaei 4y agoNo one said the computer running the simulation used digital logic. If we could encode system dynamics into "energy+matter", you could call it an analog computer without much dissent. People do this in miniature: in fact, the first computers were entirely mechanical! If we accept this reasoning to imply that the universe is a giant computer, we only have the unknowable left: was it purposefully (intelligently) designed or did it spontaneously arise? As far as I can tell, the probability of either outcome is equal according to our limited experiences, and we will never have access to a definitive answer one way or the other.