POSITIVE GRASSMANNIAN AND POLYHEDRAL SUBDIVISIONS

© ICM 2018.All rights reserved. The nonnegative Grassmannian is a cell complex with rich geometric, algebraic, and combinatorial structures. Its study involves interesting combinatorial objects, such as positroids and plabic graphs. Remarkably, the same combinatorial structures appeared in many othe...

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Main Author: POSTNIKOV, ALEXANDER
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:English
Published: WORLD SCIENTIFIC 2021
Online Access:https://hdl.handle.net/1721.1/137044
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author POSTNIKOV, ALEXANDER
author2 Massachusetts Institute of Technology. Department of Mathematics
author_facet Massachusetts Institute of Technology. Department of Mathematics
POSTNIKOV, ALEXANDER
author_sort POSTNIKOV, ALEXANDER
collection MIT
description © ICM 2018.All rights reserved. The nonnegative Grassmannian is a cell complex with rich geometric, algebraic, and combinatorial structures. Its study involves interesting combinatorial objects, such as positroids and plabic graphs. Remarkably, the same combinatorial structures appeared in many other areas of mathematics and physics, e.g., in the study of cluster algebras, scattering amplitudes, and solitons. We discuss new ways to think about these structures. In particular, we identify plabic graphs and more general Grassmannian graphs with polyhedral subdivisions induced by 2-dimensional projections of hypersimplices. This implies a close relationship between the positive Grassmannian and the theory of fiber polytopes and the generalized Baues problem. This suggests natural extensions of objects related to the positive Grassmannian.
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spelling mit-1721.1/1370442023-04-14T15:44:21Z POSITIVE GRASSMANNIAN AND POLYHEDRAL SUBDIVISIONS POSTNIKOV, ALEXANDER Massachusetts Institute of Technology. Department of Mathematics © ICM 2018.All rights reserved. The nonnegative Grassmannian is a cell complex with rich geometric, algebraic, and combinatorial structures. Its study involves interesting combinatorial objects, such as positroids and plabic graphs. Remarkably, the same combinatorial structures appeared in many other areas of mathematics and physics, e.g., in the study of cluster algebras, scattering amplitudes, and solitons. We discuss new ways to think about these structures. In particular, we identify plabic graphs and more general Grassmannian graphs with polyhedral subdivisions induced by 2-dimensional projections of hypersimplices. This implies a close relationship between the positive Grassmannian and the theory of fiber polytopes and the generalized Baues problem. This suggests natural extensions of objects related to the positive Grassmannian. 2021-11-01T18:50:23Z 2021-11-01T18:50:23Z 2019-05 2021-05-26T11:55:33Z Article http://purl.org/eprint/type/ConferencePaper https://hdl.handle.net/1721.1/137044 POSTNIKOV, ALEXANDER. 2019. "POSITIVE GRASSMANNIAN AND POLYHEDRAL SUBDIVISIONS." Proceedings of the International Congress of Mathematicians, ICM 2018, 4. en 10.1142/9789813272880_0177 Proceedings of the International Congress of Mathematicians, ICM 2018 Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf WORLD SCIENTIFIC arXiv
spellingShingle POSTNIKOV, ALEXANDER
POSITIVE GRASSMANNIAN AND POLYHEDRAL SUBDIVISIONS
title POSITIVE GRASSMANNIAN AND POLYHEDRAL SUBDIVISIONS
title_full POSITIVE GRASSMANNIAN AND POLYHEDRAL SUBDIVISIONS
title_fullStr POSITIVE GRASSMANNIAN AND POLYHEDRAL SUBDIVISIONS
title_full_unstemmed POSITIVE GRASSMANNIAN AND POLYHEDRAL SUBDIVISIONS
title_short POSITIVE GRASSMANNIAN AND POLYHEDRAL SUBDIVISIONS
title_sort positive grassmannian and polyhedral subdivisions
url https://hdl.handle.net/1721.1/137044
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