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Related papers: Embedding bumpless pipedreams as Bruhat chains

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In this paper, we establish a new geometric setting for bumpless pipe dreams and double Schubert polynomials. Building on the notion of bumpless pipe dream fragments, we define clan polynomials as their weight generating functions. It turns…

Combinatorics · Mathematics 2025-11-25 Yiming Chen , Neil J. Y. Fan , Rui Xiong , Ming Yao

We give the formula for multiplying a Schubert class on an odd orthogonal or symplectic flag manifold by a special Schubert class pulled back from a Grassmannian of maximal isotropic subspaces. This is also the formula for multiplying a…

Combinatorics · Mathematics 2016-11-08 Nantel Bergeron , Frank Sottile

We establish the formula for multiplication by the class of a special Schubert variety in the integral cohomology ring of the flag manifold. This formula also describes the multiplication of a Schubert polynomial by either an elementary…

alg-geom · Mathematics 2008-02-03 Frank Sottile

We give a new proof that three families of polynomials coincide: the double Schubert polynomials of Lascoux and Sch\"utzenberger defined by divided difference operators, the pipe dream polynomials of Bergeron and Billey, and the equivariant…

Combinatorics · Mathematics 2022-02-08 Allen Knutson

We develop a family of new combinatorial models for key polynomials. It is similar to the hybrid pipe dream model for Schubert polynomials defined recently by Knutson and Udell.

Combinatorics · Mathematics 2025-10-15 Yihan Xiao , Rui Xiong , Haofeng Zhang

Schubert polynomials for the classical groups were defined by S.Billey and M.Haiman in 1995; they are polynomial representatives of Schubert classes in a full flag variety of a classical group. We provide a combinatorial description for…

Combinatorics · Mathematics 2022-09-15 Evgeny Smirnov , Anna Tutubalina

In their work on the infinite flag variety, Lam, Lee, and Shimozono (2018) introduced objects called bumpless pipe dreams and used them to give a formula for double Schubert polynomials. We extend this formula to the setting of K-theory,…

Combinatorics · Mathematics 2020-03-17 Anna Weigandt

We give an elementary approach utilizing only the divided difference formalism for obtaining expansions of Schubert polynomials that are manifestly nonnegative, by studying solutions to the equation $\sum Y_i\partial_i=\mathrm{id}$ on…

Combinatorics · Mathematics 2025-07-09 Philippe Nadeau , Hunter Spink , Vasu Tewari

Schubert polynomials are a basis for the polynomial ring that represent Schubert classes for the flag manifold. In this paper, we introduce and develop several new combinatorial models for Schubert polynomials that relate them to other…

Combinatorics · Mathematics 2020-03-05 Sami Assaf

The aim of this article is to link Schubert varieties in the flag manifold with hyperplane arrangements. For a permutation, we construct a certain graphical hyperplane arrangement. We show that the generating function for regions of this…

Combinatorics · Mathematics 2007-09-21 Suho Oh , Alexander Postnikov , Hwanchul Yoo

Motivated by classical combinatorial Schubert calculus on the Grassmannian, Huang--Pylyavskyy introduced a generalized theory of Robinson-Schensted-Knuth (RSK) correspondence for studying Schubert calculus on the complete flag variety via…

Combinatorics · Mathematics 2023-12-04 Daoji Huang , Son Nguyen

We show that the Hilbert space with basis indexed by infinite permutations and the cohomology ring of the infinite flag variety can be seen as representations of the Heisenberg algebra, which are isomorphic using the back-stable Schubert…

Combinatorics · Mathematics 2024-10-01 Sylvester W. Zhang

Knutson and Miller (2005) established a connection between the anti-diagonal Gr\"obner degenerations of matrix Schubert varieties and the pre-existing combinatorics of pipe dreams. They used this correspondence to give a…

Commutative Algebra · Mathematics 2023-01-19 Patricia Klein

The main goal of this paper is to extend two fundamental combinatorial results in Schubert calculus on flag manifolds from equivariant cohomology and $K$-theory to equivariant elliptic cohomology. The foundations of elliptic Schubert…

Combinatorics · Mathematics 2025-10-07 Cristian Lenart , Rui Xiong , Changlong Zhong

We study the factorization of Schubert polynomials into elementary symmetric polynomials. We conjecture that this occurs when the permutation corresponding to the Schubert polynomial does not contain the patterns $1432$, $1423$, $4132$, and…

Combinatorics · Mathematics 2025-11-21 Oma Makhija

We introduce flag positroid pipe dreams (FPPs), whose role in the study of complete flag positroids is analogous to the role of Le-diagrams in the study of positroids. We develop the combinatorics of these diagrams and highlight some of…

Combinatorics · Mathematics 2026-05-26 Williem Rizer , Martha Yip

Schubert polynomials form a basis of all polynomials and appear in the study of cohomology rings of flag manifolds. The vanishing problem for Schubert polynomials asks if a coefficient of a Schubert polynomial is zero. We give a tableau…

Combinatorics · Mathematics 2021-09-13 Anshul Adve , Colleen Robichaux , Alexander Yong

The variety of complete quadrics is the wonderful compactification of $GL_n/O_n$ and admits a cell decomposition into Borel orbits indexed by combinatorial objects called $\mu$-involutions. We study Coxeter-theoretic properties of…

Combinatorics · Mathematics 2026-04-07 Jack Chen-An Chou , Zachary Hamaker

We describe an elementary convex geometric algorithm for realizing Schubert cycles in complete flag varieties by unions of faces of polytopes. For GL_n and Gelfand--Zetlin polytopes, combinatorics of this algorithm coincides with that of…

Algebraic Geometry · Mathematics 2019-02-08 Valentina Kiritchenko

We construct an integrable colored six-vertex model whose partition function is a double Grothendieck polynomial. This gives an integrable systems interpretation of bumpless pipe dreams and recent results of Weigandt [arXiv:2003.07342]…

Combinatorics · Mathematics 2021-01-05 Valentin Buciumas , Travis Scrimshaw