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Related papers: Computing toric degenerations of flag varieties

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We study the $\bG_a^M$ degenerations $\Fl^a_\la$ of the type $A$ flag varieties $\Fl_\la$. We describe these degenerations explicitly as subvarieties in the products of Grassmanians. We construct cell decompositions of $\Fl^a_\la$ and show…

Algebraic Geometry · Mathematics 2011-01-17 Evgeny Feigin

We prove that the initial degenerations of the flag variety admit closed immersions into finite inverse limits of flag matroid strata, where the diagrams are derived from matroidal subdivisions of a suitable flag matroid polytope. As an…

Algebraic Geometry · Mathematics 2026-01-14 Daniel Corey , Jorge Alberto Olarte

We construct polyhedral families of valuations on the branching algebra of a morphism of reductive groups. This establishes a connection between the combinatorial rules for studying a branching problem and the tropical geometry of the…

Algebraic Geometry · Mathematics 2012-08-29 Christopher Manon

We study Gr\"obner degenerations of Schubert varieties inside flag varieties. We consider toric degenerations of flag varieties induced by matching fields and semi-standard Young tableaux. We describe an analogue of matching field ideals…

Commutative Algebra · Mathematics 2020-09-08 Oliver Clarke , Fatemeh Mohammadi

We construct a family of compactifications of the affine cone of the Grassmannian variety of 2-planes. We show that both the tropical variety of the Pl\"ucker ideal and familiar valuations associated to the construction of Newton-Okounkov…

Algebraic Geometry · Mathematics 2019-01-15 Christopher Manon , Jihyeon Jessie Yang

We show that the counting of rational curves on a complete toric variety that are in general position to the toric prime divisors coincides with the counting of certain tropical curves. The proof is algebraic-geometric and relies on…

Algebraic Geometry · Mathematics 2007-05-23 Takeo Nishinou , Bernd Siebert

In this paper we calculate fundamental groups (and some of their quotients) of complements of four toric varieties branch curves. For these calculations, we study properties and degenerations of these toric varieties and the braid…

Geometric Topology · Mathematics 2009-09-29 M. Amram , S. Ogata

We show that the moduli space of stable n-pointed rational curves can be flatly degenerated to a projective toric variety. We arrive at this by showing that the Chow quotients of the Grassmannians admit toric degenerations, which in turn,…

Algebraic Geometry · Mathematics 2007-05-23 Yi Hu

We define a toric degeneration of an integrable system on a projective manifold, and prove the existence of a toric degeneration of the Gelfand-Cetlin system on the flag manifold of type A. As an application, we calculate the potential…

Symplectic Geometry · Mathematics 2009-06-05 Takeo Nishinou , Yuichi Nohara , Kazushi Ueda

We study standard monomial bases for Richardson varieties inside the flag variety. In general, writing down a standard monomial basis for a Richardson variety can be challenging, as it involves computing so-called defining chains or key…

Algebraic Geometry · Mathematics 2022-05-10 Narasimha Chary Bonala , Oliver Clarke , Fatemeh Mohammadi

We construct motivic invariants of a subvariety of an algebraic torus from its tropicalization and initial degenerations. More specifically, we introduce an invariant of a compactification of such a variety called the "tropical motivic…

Algebraic Geometry · Mathematics 2019-02-20 Eric Katz , Alan Stapledon

We continue, generalize and expand our study of linear degenerations of flag varieties from [G. Cerulli Irelli, X. Fang, E. Feigin, G. Fourier, M. Reineke, Math. Z. 287 (2017), no. 1-2, 615-654]. We realize partial flag varieties as quiver…

Algebraic Geometry · Mathematics 2019-02-01 Giovanni Cerulli Irelli , Xin Fang , Evgeny Feigin , Ghislain Fourier , Markus Reineke

We develop a theory of multi-stage degenerations of toric varieties over finite rank valuation rings, extending the Mumford--Gubler theory in rank one. Such degenerations are constructed from fan-like structures over totally ordered abelian…

Algebraic Geometry · Mathematics 2018-05-16 Tyler Foster , Dhruv Ranganathan

We study the toric degeneration of Weyl group translated Schubert divisors of a partial flag variety of Lie type A via Gelfand-Cetlin polytopes. We propose a conjecture that Schubert varieties of appropriate dimensions intersect…

Algebraic Geometry · Mathematics 2021-12-24 DongSeon Hwang , Hwayoung Lee , Jae-Hyouk Lee , Changzheng Li

In this article, we present a massively parallel framework for computing tropicalizations of algebraic varieties which can make use of finite symmetries. We compute the tropical Grassmannian TGr$_0(3,8)$, and show that it refines the…

Algebraic Geometry · Mathematics 2020-04-02 Dominik Bendle , Janko Boehm , Yue Ren , Benjamin Schröter

A toric degeneration in algebraic geometry is a process where a given projective variety is being degenerated into a toric one. Then one can obtain information about the original variety via analyzing the toric one, which is a much easier…

Symplectic Geometry · Mathematics 2018-12-31 Milena Pabiniak

We study the combinatorics of Gr\"obner degenerations of Grassmannians and the Schubert varieties inside them. We provide a family of binomial ideals whose combinatorics is governed by tableaux induced by matching fields in the sense of…

Commutative Algebra · Mathematics 2020-09-15 Oliver Clarke , Fatemeh Mohammadi

Let X \subset Proj(V) be a projective spherical G-variety, where V is a finite dimensional G-module and G = SP(2n, C). In this paper, we show that X can be deformed, by a flat deformation, to the toric variety corresponding to a convex…

Algebraic Geometry · Mathematics 2007-05-23 Kiumars Kaveh

Using the method of degenerating a Grassmannian into a toric variety, we calculate recursive formulas for the dimensions of the eigenspaces of the action of an n-dimensional torus on a Grassmannian of planes in an n-dimensional space. In…

Algebraic Geometry · Mathematics 2012-09-18 Jakub Witaszek

We introduce iterated sequences for Grassmannians, a new class of Fang-Fourier-Littelmanns' birational sequences and explain how they give rise to points in $\text{trop}(\text{Gr}(k,\mathbb C^n))$, Speyer-Sturmfels' tropical Grassmannian.…

Representation Theory · Mathematics 2021-05-12 Lara Bossinger