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Amplituhedrons---can this really make locality and unitarity emergent properties?
Amplituhedrons are now probably the most exciting development in theoretical physics. It's said that with amplituhedrons, perhaps finally quantum gravity can be married with quantum field theory, through removal of the need for locality and unitarity as "fundamental properties".
Any opinions about amplituhedrons?
Christopher Baird, "like Feynman diagrams". Well, let it be pointed out that QED (based on Feynamn diagrams) has become one of the most successful models in physics, today the foundation of modern particle physics. Amplituhedrons, already with a long history leading up to its development, is an improvement on QED, offering to eliminate a number of its serious shortcomings, some of which were already acknowledged by Richard Feynman decades ago.
Fred, "Amplituhedron" is so new that I don't think I can find "Amplituhedra" in any dictionary or paper. Maybe that will catch on? It seems logical to use that word for the plural form.
Neb, I've learned a long time ago that the line between "abstract mathematics" and "physical reality" is a very blurry one. Physical reality seems to follow mathematical fact, no matter how outlandish. I trust my "physical intuition" less and mathematical fact more. We only think that physical reality should be as what our physical intuition says it should be.
3 Answers
- ?Lv 78 years agoFavorite Answer
It would seem that since QFT calculations are so much simpler using the idea of amplituhedra, there must be some sort of connection to the underlying physics (reality). The question is what is that connection. The relationship between mathematics and the underlying reality of the universe is an ongoing issue in quantum mechanics illustrated by the failure of the mathematics to unambiguously describe reality (many-worlds, Copenhagen, pilot wave, transactional, etc)
The basic assumption of non-locality is not too troubling, since even the conventional view of quantum mechanics is non-local (wave function collapse, entanglement, etc.). The assumption that we can cast off unitarity is a lot more troubling and needs to have some physical basis. In fact, both non-locality and no requirement for unitarity seem to be key and must have their physical nature described, rather than assumed, for amplituhedra to be anything more than a useful mathematical tool with no basis in reality.
- ?Lv 58 years ago
I think they are greatly overhyped. There is no *proof* at this point that they can marry gravity and quantum theory, only the hope that they can. Right now, we only have evidence that Amplituhedrons are nothing more than a clever, quicker way of solving certain equations, much like Feynman diagrams.
- 6 years ago
I don't understand why people say Amlplituhedron is a very basic discovery . in many of theories of QG (Loop quantum gravity,group field theory,causal set ,...), it is expected that notions such as time,space,causality , locality ,unitarity and even geometry itself be emergent concepts and so Amplituhedron in not unique at all in this term . I think there exist some QG that even go further than it and make more radical predictions such as replacing of very foundation of mathematics itself which is now based on set-theory with something more fundamental for example category or topos theory. Amplituhedron is combination of twistor theory and string theory and it has succeeded only in planer limit ( supersymmetric yang-mills theory ) . there is a very long way to go to the top of you want QG .
