Castelnuovo–Mumford regularity of matrix Schubert varieties

O Pechenik, DE Speyer, A Weigandt - Selecta Mathematica, 2024 - Springer
Matrix Schubert varieties are affine varieties arising in the Schubert calculus of the complete
flag variety. We give a formula for the Castelnuovo–Mumford regularity of matrix Schubert …

Gröbner geometry of Schubert polynomials through ice

Z Hamaker, O Pechenik, A Weigandt - Advances in Mathematics, 2022 - Elsevier
The geometric naturality of Schubert polynomials and their combinatorial pipe dream
representations was established by Knutson and Miller (2005) via antidiagonal Gröbner …

The permutahedral variety, mixed Eulerian numbers, and principal specializations of Schubert polynomials

P Nadeau, V Tewari - International Mathematics Research …, 2023 - academic.oup.com
We compute the expansion of the cohomology class of the permutahedral variety in the
basis of Schubert classes. The resulting structure constants are expressed as a sum of …

On sl (N) link homology with mod N coefficients

J Wang - arxiv preprint arxiv:2111.02287, 2021 - content.ems.press
We construct an operator on sl. N/link homology with coefficients in a ring whose
characteristic divides N. If P is a prime number, we use this operator to exhibit structural …

When do Schubert polynomial products stabilize?

A Hardt, D Wallach - arxiv preprint arxiv:2412.06976, 2024 - arxiv.org
The" back-stabilization number" for products of Schubert polynomials is the distance the
corresponding permutations must be shifted before the structure constants stabilize. We give …

Differential operators on Schur and Schubert polynomials

G Nenashev - arxiv preprint arxiv:2005.08329, 2020 - arxiv.org
This paper deals with decreasing operators on back stable Schubert polynomials. We study
two operators $\xi $ and $\nabla $ of degree $-1$, which satisfy the Leibniz rule …

A combinatorial 𝔰𝔩₂-action and the Sperner property for the weak order

C Gaetz, Y Gao - Proceedings of the American Mathematical Society, 2020 - ams.org
We construct a simple combinatorially-defined representation of $\mathfrak {sl} _2 $ which
respects the order structure of the weak order on the symmetric group. This is used to prove …

[HTML][HTML] Tableau posets and the fake degrees of coinvariant algebras

SC Billey, M Konvalinka, JP Swanson - Advances in Mathematics, 2020 - Elsevier
We introduce two new partial orders on the standard Young tableaux of a given partition
shape, in analogy with the strong and weak Bruhat orders on permutations. Both posets are …

A combinatorial duality between the weak and strong Bruhat orders

C Gaetz, Y Gao - Journal of Combinatorial Theory, Series A, 2020 - Elsevier
In recent work, the authors used an order lowering operator∇, introduced by Stanley, to
prove the strong Sperner property for the weak Bruhat order on the symmetric group …

The diagonal derivative of a skew Schur polynomial

D Grinberg, N Korniichuk, K Molokanov… - arxiv preprint arxiv …, 2024 - arxiv.org
We prove a formula for the image of a skew Schur polynomial $ s_ {\lambda/\mu}\left (x_ {1},
x_ {2},\ldots, x_ {N}\right) $ under the differential operator $\nabla:=\dfrac {\partial}{\partial x …