Hunter Spink

activity

20132026

most citedMotive of the moduli stack of rational curves on a weighted projective stack

4 citations · 23 across the 32 of their papers we have counts for

collaborators

37 papers

math.AG2026

Long range divided differences, clusters, and Graham-positivity

Hunter Spink, Vasu Tewari

We study torus-orbit closures in the type $A$ complete flag variety naturally associated to cones in the positive cluster fan, together with their left $S_{n}$ -translates. The torus-…

math.AG2026

The Springer Geometry of Specht Polynomials and Schubert cycle positivity for two row Springer fiber components

Hunter Spink, Vasu Tewari

We show that the type A Springer representation is realized geometrically in the homology of the complete flag variety by Specht polynomials. For any partition, we identify the cla…

math.CO2026

Grove polynomials and $K$ -theoretic quasisymmetry

Philippe Nadeau, Hunter Spink, Vasu Tewari

We define the grove polynomials, a set-valued extension of forest polynomials. We show that they are $K$ -theoretically dual to the quasisymmetric Schubert cells which pave the quas…

math.AG2026

The Quasisymmetric Grassmannian

Nantel Bergeron, Lucas Gagnon, Hunter Spink +1

We construct a complex of toric varieties we call the quasisymmetric Grassmannian inside the Grassmannian of $r$ -planes in $C^{n}$ . Each irreducible component is a positroid…

math.AG2026

The Coxeter Flag Variety

Nantel Bergeron, Lucas Gagnon, Hunter Spink +1

For a Coxeter element $c$ in a Weyl group $W$ , we define the $c$ -Coxeter flag variety $CFl_{c} \subset G / B$ as the union of left-translated Richardson varieties $w^{-1}…

math.AG2025

Fano compactifications of mutation algebras

Joshua Enwright, Luca Francone, Joaquín Moraga +1

In this article, we introduce the notion of mutation semigroup algebras. This concept simultaneously generalizes cluster algebras and semigroup algebras. We show that, under some m…

math.CO2025

Richardson tableaux and Schubert positivity

Hunter Spink, Vasu Tewari

We compute the Schubert cycle expansion of those irreducible components of Springer fibers equal to Richardson varieties. This generalizes work of Güemes in the case of a hook shap…

math.RT2025

Lattice Models for Double Whittaker Polynomials and Motivic Chern Classes

Ben Brubaker, Daniel Bump, Andrew Hardt +1

We will describe solvable lattice models whose partition functions depend on two sets of variables, $x_{1}, \dots, x_{n}$ and $y_{1}, y_{2}, \dots$ that have different connections with th…

math.AG2025

The quasisymmetric flag variety: a toric complex on noncrossing partitions

Nantel Bergeron, Lucas Gagnon, Philippe Nadeau +2

We develop the geometric theory of equivariant quasisymmetry via a new ``quasisymmetric flag variety''. This is a toric complex in the flag variety whose fixed point set is the set…

math.AG2025

Vector-valued Laurent polynomial equations, toric vector bundles and matroids

Kiumars Kaveh, Askold Khovanskii, Hunter Spink

Let $L \subset C^{r} \otimes C [x_{1}^{\pm}, \dots, x_{n}^{\pm}]$ be a finite dimensional subspace of vector-valued Laurent polynomials invariant under the action of torus…

math.CO2025

Equivariant quasisymmetry and noncrossing partitions

Nantel Bergeron, Lucas Gagnon, Philippe Nadeau +2

We introduce a definition of ``equivariant quasisymmetry'' for polynomials in two sets of variables. Using this definition we define quasisymmetric generalizations of the theory of…

math.GR2025★ 1 cited

On the number and sizes of double cosets of Sylow subgroups of the symmetric group

Persi Diaconis, Eugenio Giannelli, Robert M. Guralnick +4

Let $P_{n}$ be a Sylow $p$ -subgroup of the symmetric group $S_{n}$ . We investigate the number and sizes of the $P_{n} ∖ S_{n} / P_{n}$ double cosets, showing that most double cosets…

math.AG2024

The geometry of quasisymmetric coinvariants

Philippe Nadeau, Hunter Spink, Vasu Tewari

We develop a quasisymmetric analogue of the theory of Schubert cycles, building off of our previous work on a quasisymmetric analogue of Schubert polynomials and divided difference…

math.CO2024

Schubert polynomial expansions revisited

Philippe Nadeau, Hunter Spink, Vasu Tewari

We give an elementary approach utilizing only the divided difference formalism for obtaining expansions of Schubert polynomials that are manifestly nonnegative, by studying solutio…

math.CO2024★ 2 cited

Quasisymmetric divided differences

Philippe Nadeau, Hunter Spink, Vasu Tewari

We develop a quasisymmetric analogue of the combinatorial theory of Schubert polynomials and the associated divided difference operators. Our counterparts are "forest polynomials",…

math.CO2023★ 2 cited

K-classes of delta-matroids and equivariant localization

Christopher Eur, Matt Larson, Hunter Spink

Delta-matroids are "type B" generalizations of matroids in the same way that maximal orthogonal Grassmannians are generalizations of Grassmannians. A delta-matroid analogue of the…

math.AG2022

Algebraic and o-minimal flows beyond the cocompact case

Spencer Dembner, Hunter Spink

Let $X \subset C^{n}$ be an algebraic variety, and let $Λ \subset C^{n}$ be a discrete subgroup whose real and complex spans agree. We describe the topological closure…

math.AG2022★ 3 cited

Signed permutohedra, delta-matroids, and beyond

Christopher Eur, Alex Fink, Matt Larson +1

We establish a connection between the algebraic geometry of the type B permutohedral toric variety and the combinatorics of delta-matroids. Using this connection, we compute the vo…

math.LO2022

Multiplicative structures and random walks in o-minimal groups

Hunter Spink

We prove structure theorems for o-minimal definable subsets $S \subset G$ of definable groups containing large multiplicative structures, and show definable groups do not have bound…

math.CO2021

Geometric and o-minimal Littlewood-Offord problems

Jacob Fox, Matthew Kwan, Hunter Spink

The classical Erdős-Littlewood-Offord theorem says that for nonzero vectors $a_{1}, \dots, a_{n} \in R^{d}$ , any $x \in R^{d}$ , and uniformly random $(ξ_1,\dots,ξ_n)\in\{-1,1…

math.CO2021★ 3 cited

Tautological classes of matroids

Andrew Berget, Christopher Eur, Hunter Spink +1

We introduce certain torus-equivariant classes on permutohedral varieties which we call "tautological classes of matroids" as a new geometric framework for studying matroids. Using…

math.FA2020★ 1 cited

Sharp L1 Inequalities for Sup-Convolution

Peter van Hintum, Hunter Spink, Marius Tiba

Given a compact convex domain $C \subset R^{k}$ and bounded measurable functions $f_{1}, \dots, f_{n} : C \to R$ , define the sup-convolution $(f_{1} * \dots * f_{n}) (z)$ t…

math.AG2020★ 1 cited

Log-concavity of matroid h-vectors and mixed Eulerian numbers

Andrew Berget, Hunter Spink, Dennis Tseng

For any matroid $M$ , we compute the Tutte polynomial $T_{M} (x, y)$ using the mixed intersection numbers of certain classes in the combinatorial Chow ring $A^{∙} (M)$ arising from h…

math.NT2020

Sets in $Z^{k}$ with doubling $2^{k} + δ$ are near convex progressions

Peter van Hintum, Hunter Spink, Marius Tiba

For $δ > 0$ sufficiently small and $A \subset Z^{k}$ with $∣ A + A ∣ \leq (2^{k} + δ) ∣ A ∣$ , we show either $A$ is covered by $m_{k} (δ)$ parallel hyperplanes, or satisfies $|\widehat{\operat…

Long range divided differences, clusters, and Graham-positivity

The Springer Geometry of Specht Polynomials and Schubert cycle positivity for two row Springer fiber components

Grove polynomials and K-theoretic quasisymmetry

The Quasisymmetric Grassmannian

The Coxeter Flag Variety

Fano compactifications of mutation algebras

Richardson tableaux and Schubert positivity

Lattice Models for Double Whittaker Polynomials and Motivic Chern Classes

The quasisymmetric flag variety: a toric complex on noncrossing partitions

Vector-valued Laurent polynomial equations, toric vector bundles and matroids

Equivariant quasisymmetry and noncrossing partitions

On the number and sizes of double cosets of Sylow subgroups of the symmetric group

The geometry of quasisymmetric coinvariants

Schubert polynomial expansions revisited

Quasisymmetric divided differences

K-classes of delta-matroids and equivariant localization

Algebraic and o-minimal flows beyond the cocompact case

Signed permutohedra, delta-matroids, and beyond

Multiplicative structures and random walks in o-minimal groups

Geometric and o-minimal Littlewood-Offord problems

Tautological classes of matroids

Sharp L1 Inequalities for Sup-Convolution

Log-concavity of matroid h-vectors and mixed Eulerian numbers

Sets in Zk with doubling 2k+δ are near convex progressions

Grove polynomials and $K$ -theoretic quasisymmetry

Sets in $Z^{k}$ with doubling $2^{k} + δ$ are near convex progressions