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Pipe dreams and bumpless pipe dreams for vexillary permutations are each known to be in bijection with certain semistandard tableaux via maps due to Lenart and Weigandt, respectively. Recently, Gao and Huang have defined a bijection between…

Combinatorics · Mathematics 2022-07-04 Adam Gregory , Zachary Hamaker

In recent work, Hamaker, Pechenik, Speyer, and Weigandt showed that a certain differential operator $\nabla$ expands positively in the basis of Schubert polynomials. For $\pi$ a dominant permutation, Gaetz and Tung showed an analogous…

Combinatorics · Mathematics 2025-08-19 Hugh Dennin

In our previous work we have introduced an analogue of Robinson-Schensted-Knuth correspondence for Schubert calculus of the complete flag varieties. The objects inserted are certain biwords, the outcomes of insertion are bumpless pipe…

Combinatorics · Mathematics 2023-04-17 Daoji Huang , Pavlo Pylyavskyy

Bumpless pipe dreams (BPDs) are combinatorial objects used in the study of Schubert and Grothendieck polynomials. Weigandt recently introduced a co-BPD object associated to each BPD and used them to give an analogue to the change of bases…

Combinatorics · Mathematics 2026-01-01 Joshua Arroyo , Adam Gregory

Schubert polynomials represent a basis for the cohomology of the complete flag variety and thus play a central role in geometry and combinatorics. In this context, Schubert polynomials are generating functions over various combinatorial…

Combinatorics · Mathematics 2025-01-30 Sarah Gold , Elizabeth Milićević , Yuxuan Sun

We characterize totally symmetric self-complementary plane partitions (TSSCPP) as bounded compatible sequences satisfying a Yamanouchi-like condition. As such, they are in bijection with certain pipe dreams. Using this characterization and…

Combinatorics · Mathematics 2024-02-06 Daoji Huang , Jessica Striker

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

The Cauchy identity gives a recipe for decomposing a double Grothendieck polynomial $\mathfrak{G}^{(\beta)}_w(x;y)$ as a sum of products $\mathfrak{G}^{(\beta)}_v(x)\mathfrak{G}^{(\beta)}_u(y)$ of single Grothendieck polynomials.…

Combinatorics · Mathematics 2025-06-27 Hugh Dennin

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

We introduce analogs of left and right RSK insertion for Schubert calculus of complete flag varieties. The objects being inserted are certain biwords, the insertion objects are bumpless pipe dreams, and the recording objects are decorated…

Combinatorics · Mathematics 2022-06-30 Daoji Huang , Pavlo Pylyavskyy

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 geometric naturality of Schubert polynomials and their combinatorial pipe dream representations was established by Knutson and Miller (2005) via antidiagonal Gr\"obner degeneration of matrix Schubert varieties. We consider instead…

Combinatorics · Mathematics 2022-03-25 Zachary Hamaker , Oliver Pechenik , Anna Weigandt

Kazhdan-Lusztig ideals, a family of generalized determinantal ideals investigated in [Woo-Yong '08], provide an explicit choice of coordinates and equations encoding a neighbourhood of a torus-fixed point of a Schubert variety on a type A…

Combinatorics · Mathematics 2012-07-31 Alexander Woo , Alexander Yong

The classical Hilbert specialization property is a field-theoretic tool ensuring that polynomial irreducibility over a field is preserved under specialization of some of the variables. We develop an integral counterpart by introducing the…

Number Theory · Mathematics 2026-04-09 Angelot Behajaina , Pierre Dèbes , Joachim König

In the space of equioriented type $A$ quiver representations, we define subvarieties called "open quiver loci" by placing strict rank conditions on the maps within representations. The closures of these subvarieties are the quiver loci,…

Combinatorics · Mathematics 2026-05-25 Moriah Elkin

The ring of symmetric functions can be implemented in the homology of \union_{a,b} Gr(a,a+b), the multiplicative structure being defined from the "direct sum" map. There is a natural circle action (simultaneously on all Grassmannians) under…

Algebraic Geometry · Mathematics 2015-03-16 Allen Knutson , Mathias Lederer

We give an algebra-combinatorial constructions of (noncommutative) generating functions of double Schubert and double $\beta$-Grothendieck polynomials corresponding to the full flag varieties associated to the Lie groups of classical types…

Combinatorics · Mathematics 2015-04-08 A. N. Kirillov

Motivated by questions originating from the study of a class of shallow student-teacher neural networks, methods are developed for the analysis of spurious minima in classes of gradient equivariant dynamics related to neural nets. In the…

Machine Learning · Computer Science 2022-06-22 Yossi Arjevani , Michael Field

In this paper we show that the pipe dream complex associated to the permutation 1n(n-1)...2 can be geometrically realized as a triangulation of the vertex figure of a root polytope. Leading up to this result we show that the Grothendieck…

Combinatorics · Mathematics 2015-11-02 Karola Mészáros

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