English
Related papers

Related papers: Combinatorial mutations of Newton-Okounkov polytop…

200 papers

We investigate the plabic graphs corresponding to the quadrilateral Postnikov arrangements used by J.Scott to equip the homogeneous coordinate rings of Grassmannians with a cluster structure. More precisely we describe their orbits under…

Combinatorics · Mathematics 2025-01-22 Michael Schlößer

Matching fields were introduced by Sturmfels and Zelevinsky to study certain Newton polytopes and more recently have been shown to give rise to toric degenerations of various families of varieties. Whenever a matching field gives rise to a…

Combinatorics · Mathematics 2020-10-09 Oliver Clarke , Akihiro Higashitani , Fatemeh Mohammadi

A Newton-Okounkov body is a convex body constructed from a projective variety with a globally generated line bundle and with a higher rank valuation on the function field, which gives a systematic method of constructing toric degenerations…

Representation Theory · Mathematics 2025-07-24 Naoki Fujita , Akihiro Higashitani

The Gelfand-Tsetlin and the Feigin-Fourier-Littelmann-Vinberg polytopes for the Grassmannians are defined, from the perspective of representation theory, to parametrize certain bases for highest weight irreducible modules. These polytopes…

Combinatorics · Mathematics 2022-08-10 Oliver Clarke , Akihiro Higashitani , Fatemeh Mohammadi

We study toric degenerations arising from Gr\"obner degenerations or the tropicalization of partial flag varieties. We produce a new family of toric degenerations of partial flag varieties whose combinatorics are governed by matching fields…

Algebraic Geometry · Mathematics 2023-10-12 Oliver Clarke , Fatemeh Mohammadi , Francesca Zaffalon

The theory of Newton-Okounkov bodies is a generalization of that of Newton polytopes for toric varieties, and it gives a systematic method of constructing toric degenerations of projective varieties. In this paper, we study Newton-Okounkov…

Representation Theory · Mathematics 2025-07-25 Naoki Fujita , Hironori Oya

The theory of Newton-Okounkov polytopes is a generalization of that of Newton polytopes for toric varieties, and it gives a systematic method of constructing toric degenerations of a projective variety. In the case of Schubert varieties,…

Algebraic Geometry · Mathematics 2017-03-10 Naoki Fujita

Motivated by the construction of Newton--Okounkov bodies and toric degenerations via cluster algebras in [GHKK18, FO25], we consider a family of Newton--Okounkov polytopes of a complex smooth Fano variety $X$ related by a composition of…

Symplectic Geometry · Mathematics 2025-08-07 Yunhyung Cho , Myungho Kim , Yoosik Kim , Euiyong Park

The homogeneous coordinate ring of the Grassmannian Gr(k,n) has a cluster structure defined in terms of planar diagrams known as Postnikov diagrams. The cluster corresponding to such a diagram consists entirely of Pluecker coordinates. We…

Combinatorics · Mathematics 2020-12-21 Bethany Marsh , Jeanne Scott

We give an explicit combinatorial description of cluster structures in Schubert varieties of the Grassmannian in terms of (target labelings of) Postnikov's plabic graphs. This description is a natural generalization of the description given…

Combinatorics · Mathematics 2018-11-08 Khrystyna Serhiyenko , Melissa Sherman-Bennett , Lauren Williams

Tropical geometry and the theory of Newton-Okounkov bodies are two methods which produce toric degenerations of an irreducible complex projective variety. Kaveh-Manon showed that the two are related. We give geometric maps between the…

Algebraic Geometry · Mathematics 2021-07-05 Laura Escobar , Megumi Harada

A plabic graph is a planar bicolored graph embedded in a disk, which satisfies some combinatorial conditions. Postnikov's boundary measurement map takes the space of positive edge weights of a plabic graph $G$ to a positroid cell in some…

Combinatorics · Mathematics 2017-03-21 Rachel Karpman , Yi Su

We use cluster structures and mirror symmetry to explicitly describe a natural class of Newton-Okounkov bodies for Grassmannians. We consider the Grassmannian $X=Gr_{n-k}(\mathbb C^n)$, as well as the mirror dual Landau-Ginzburg model…

Algebraic Geometry · Mathematics 2019-12-19 Konstanze Rietsch , Lauren Williams

In this article we explain how the coordinate ring of each (open) Schubert variety in the Grassmannian can be identified with a cluster algebra, whose combinatorial structure is encoded using (target labelings of) Postnikov's plabic graphs.…

Combinatorics · Mathematics 2019-08-07 K. Serhiyenko , M. Sherman-Bennett , L. Williams

Plabic graphs are interesting combinatorial objects used to study the totally nonnegative Grassmannian. Faces of plabic graphs are labeled by $k$-element sets of positive integers, and a collection of such $k$-element sets are the face…

Combinatorics · Mathematics 2014-05-21 SuHo Oh , David E Speyer

The purpose of this note is to connect two maps related to certain graphs embedded in the disc. The first is Postnikov's boundary measurement map, which combines partition functions of matchings in the graph into a map from an algebraic…

Combinatorics · Mathematics 2017-11-22 Greg Muller , David E Speyer

The Grassmannian is a disjoint union of open positroid varieties $P_v$, certain smooth irreducible subvarieties whose definition is motivated by total positivity. The coordinate ring of $P_v$ is a cluster algebra, and each reduced plabic…

Combinatorics · Mathematics 2022-01-07 Chris Fraser , Melissa Sherman-Bennett

We give a combinatorial interpretation for certain cluster variables in Grassmannian cluster algebras in terms of double and triple dimer configurations. More specifically, we examine several Gr(3,n) cluster variables that may be written as…

Combinatorics · Mathematics 2024-04-30 Moriah Elkin , Gregg Musiker , Kayla Wright

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…

Combinatorics · Mathematics 2018-06-15 Alexander Postnikov

Plabic graphs are intimately connected to the positroid stratification of the positive Grassmannian. The duals to these graphs are quivers, and it is possible to associate to them cluster algebras. For the top-cell graph of $Gr_{+}(k,n)$,…

High Energy Physics - Theory · Physics 2015-06-22 Miguel F. Paulos , Burkhard U. W. Schwab
‹ Prev 1 2 3 10 Next ›