Root polytopes, Tutte polynomials, and a duality theorem for bipartite graphs

Let G be a connected bipartite graph with colour classes E and V and root polytope Q. Regarding the hypergraph H=(V,E) induced by G, we prove that the interior polynomial of H is equivalent to the Ehrhart polynomial of Q, which in turn is equivalent to the h-vector of any triangulation of Q. It foll...

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Bibliographic Details
Main Authors: Kalman, Tamas (Contributor), Postnikov, Alexander (Contributor)
Other Authors: Massachusetts Institute of Technology. Department of Mathematics (Contributor)
Format: Article
Language:English
Published: Oxford University Press (OUP), 2018-05-30T18:48:50Z.
Subjects:
Online Access:Get fulltext
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042 |a dc 
100 1 0 |a Kalman, Tamas  |e author 
100 1 0 |a Massachusetts Institute of Technology. Department of Mathematics  |e contributor 
100 1 0 |a Kalman, Tamas  |e contributor 
100 1 0 |a Postnikov, Alexander  |e contributor 
700 1 0 |a Postnikov, Alexander  |e author 
245 0 0 |a Root polytopes, Tutte polynomials, and a duality theorem for bipartite graphs 
260 |b Oxford University Press (OUP),   |c 2018-05-30T18:48:50Z. 
856 |z Get fulltext  |u http://hdl.handle.net/1721.1/115992 
520 |a Let G be a connected bipartite graph with colour classes E and V and root polytope Q. Regarding the hypergraph H=(V,E) induced by G, we prove that the interior polynomial of H is equivalent to the Ehrhart polynomial of Q, which in turn is equivalent to the h-vector of any triangulation of Q. It follows that the interior polynomials of H and its transpose H=(E,V) agree. When G is a complete bipartite graph, our result recovers a well-known hypergeometric identity due to Saalschütz. It also implies that certain extremal coefficients in the Homfly polynomial of a special alternating link can be read off of an associated Floer homology group. 
520 |a National Science Foundation (U.S.) (Grant DMS‐1100147) 
520 |a National Science Foundation (U.S.) (Grant DMS‐1362336) 
655 7 |a Article 
773 |t Proceedings of the London Mathematical Society