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Results for amplituhedron
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75 votes
4 answers
6k views

What is the amplituhedron?

My question is quite simple: what is the mathematical definition of the amplituhedron? … An older-sister MO question: The amplituhedron minus the physics Update: The paper The amplituhedron by Nima Arkani-Hamed and Jaroslav Trnka is now on the arxive. …
Gil Kalai's user avatar
  • 24.7k
72 votes
2 answers
9k views

The amplituhedron minus the physics

Is it possible to appreciate the geometric/polytopal properties of the amplituhedron without delving into the physics that gave rise to it? …
Joseph O'Rourke's user avatar
3 votes
0 answers
222 views

Definition of loop amplituhedrons

In the paper The Amplituhedron , Nima Arkani-Hamed and Jaroslav Trnka introduced the geometric object amplituhedron. It is defined as follows (see also the lecture notes). … The tree amplituhedron $\mathcal{A}_{n,k,m}$ is the image $\tilde{Z}(Gr_{k,n}^{\geq 0}) \subset Gr_{k,k+m}$. …
Jianrong Li's user avatar
  • 6,211
1 vote
1 answer
1k views

The stock market polytope: explanation?

(The situation is reminiscent of "The amplituhedron minus the physics"...)       …
Joseph O'Rourke's user avatar
7 votes
0 answers
691 views

Update on "A Mad day's work" by Cartier

There have been many exciting dual representations of amplitudes including polytopes, twistor diagrams and the positive grassmannian leading to the concept of the amplituhedron, polylogs, multizeta …
Tom Copeland's user avatar
  • 10.5k
8 votes

What is the amplituhedron?

See http://www.twistordiagrams.org.uk/papers/index.html for the description of historical developments that led to the discovery of amplituhedron. … Other useful information can be found at http://ncatlab.org/nlab/show/amplituhedron
Zurab Silagadze's user avatar
7 votes

What is the amplituhedron?

He also briefly referred to the amplituhedron. … Video1, Video2, Video3, Video4 Postnikov's ten minutes explanation of the amplituhedron starts here. …
Gil Kalai's user avatar
  • 24.7k
32 votes

What is the amplituhedron?

The construction of the amplituhedron $P_{n,k,m}$ is summarized on page 23. … This space is called the amplituhedron. …
Carlo Beenakker's user avatar
4 votes

The amplituhedron minus the physics

He also briefly referred to the amplituhedron. … Video1, Video2, Video3, Video4 Postnikov's ten minutes explanation of the amplituhedron starts here. …
Gil Kalai's user avatar
  • 24.7k
54 votes
Accepted

The amplituhedron minus the physics

, in which the amplituhedron is Zariski-dense). … The principal job of the amplituhedron is to help nail down this form: the form is required to be well-defined on the interior of the amplituhedron. …
Logan M's user avatar
  • 1,063
1 vote
Accepted

An Intriguing Tapestry: Number triangles, polytopes, Grassmannians, and scattering amplitudes

There’s a simpler (and older) Amplituhedron-like object called the associahedron that can be thought of as what the Amplituhedron looks like on the surface of a string, and CHY’s setup can be thought of … as a sophisticated map that takes this object and turns it into the Amplituhedron." …
Tom Copeland's user avatar
  • 10.5k
7 votes
3 answers
2k views

An Intriguing Tapestry: Number triangles, polytopes, Grassmannians, and scattering amplitudes

What are the roles that the classic number arrays-- Eulerian, Narayana--play in the application of totally non-negative Grassmannians, or amplituhedrons, to string / twistor scattering theory? (This …
Tom Copeland's user avatar
  • 10.5k
8 votes
1 answer
1k views

What is the "Tangle" at the Heart of Quantum Simulation?

Goncharov, Alexander Postnikov, and Jaroslav Trnka (arXiv:1212.5605 [hep-th]), coauthor Arkani-Hamed asserted the following research objective in an associated lecture The Amplituhedron: We can't just … class of non-Hilbert dynamical systems in which unitarity and locality are encoded emergently, in geometric objects called amplituhedrons — for details see Gil Kalai's MathOverflow question "What is the amplituhedron
3 votes
0 answers
107 views

Non-tree models of Lagrange inversion polynomials

On the other hand, Lukowski, Parisi, and Williams assert on p. 35 of "The positive tropical Grassmannian, the hypersimplex, and the m=2 amplituhedron" that the f-vectors of $Trop^+$ $Gr_{2,n}$ are those …
Tom Copeland's user avatar
  • 10.5k
2 votes

Guises of the Stasheff polytopes, associahedra for the Coxeter $A_n$ root system?

Nima Arkani-Hamed, Yuntao Bai, Song He, and Gongwang Yan: The search for a theory of the S-Matrix has revealed surprising geometric structures underlying amplitudes ranging from the worldsheet to the amplituhedron
Tom Copeland's user avatar
  • 10.5k