English
Related papers

Related papers: Regular nilpotent partial Hessenberg varieties

200 papers

Dale Peterson has discovered a surprising result that the quantum cohomology ring of the flag variety $\mbox{GL}_n(\mathbb{C})/B$ is isomorphic to the coordinate ring of the intersection of the Peterson variety $\mbox{Pet}_n$ and the…

Algebraic Geometry · Mathematics 2025-02-19 Tatsuya Horiguchi , Tomoaki Shirato

For an endomorphism $s:V\rightarrow V$ of a finite dimensional complex vector space and an action of a torus $T$ on the full flag variety $\text{GL}_n({\mathbb C})/B$, we give a description of its fixed point set when $s$ is semisimple or…

Algebraic Geometry · Mathematics 2022-02-08 Daniel Sánchez Argáez , Felipe Zaldívar

Let G be a complex semisimple linear algebraic group and let Pet be the associated Peterson variety in the flag variety G/B. The main theorem of this note gives an efficient presentation of the equivariant cohomology ring H^*_S(Pet) of the…

Algebraic Geometry · Mathematics 2019-08-15 Megumi Harada , Tatsuya Horiguchi , Mikiya Masuda

We construct a concrete isomorphism from the permutohedral variety to the regular semisimple Hessenberg variety associated to the Hessenberg function $h_+(i)=i+1$, $1\le i\le n-1$. In the process of defining the isomorphism, we introduce a…

Algebraic Geometry · Mathematics 2022-10-13 Jan-Li Lin

Let $G$ be a simple, simply-connected complex algebraic group with Lie algebra $\mathfrak{g}$, and $G/B$ the associated complete flag variety. The Hochschild cohomology $HH^\bullet(G/B)$ is a geometric invariant of the flag variety related…

Representation Theory · Mathematics 2025-01-17 Sam Jeralds

We study geometric and topological properties of Hessenberg varieties of codimension one in the type A flag variety. Our main results: (1) give a formula for the Poincar\'e polynomial, (2) characterize when these varieties are irreducible,…

Algebraic Geometry · Mathematics 2026-04-22 Laura Escobar , Martha Precup , John Shareshian

In this paper we consider certain closed subvarieties of the flag variety, known as Hessenberg varieties. We prove that Hessenberg varieties corresponding to nilpotent elements which are regular in a Levi factor are paved by affines. We…

Algebraic Geometry · Mathematics 2012-05-29 Martha Precup

The polynomials $f_{i,j}$ are introduced by Abe-Harada-Horiguchi-Masuda to produce an explicit presentation by generators and relations of the cohomology rings of regular nilpotent Hessenberg varieties. In this paper we quantize the…

Algebraic Geometry · Mathematics 2025-12-15 Tatsuya Horiguchi

A regular nilpotent Hessenberg Schubert cell is the intersection of a regular nilpotent Hessenberg variety with a Schubert cell. In this paper, we describe a set of minimal generators of the defining ideal of a regular nilpotent Hessenberg…

Algebraic Geometry · Mathematics 2024-03-06 Mike Cummings , Sergio Da Silva , Megumi Harada , Jenna Rajchgot

This manuscript is a contributed chapter in the forthcoming CRC Press volume, titled the Handbook of Combinatorial Algebraic Geometry: Subvarieties of the Flag Variety. The book, as a whole, is aimed at a diverse audience of researchers and…

Algebraic Geometry · Mathematics 2024-07-17 Megumi Harada , Tatsuya Horiguchi

This work pursues a circle of Lie-theoretic ideas involving Hessenberg varieties, Poisson geometry, and wonderful compactifications. In more detail, one may associate a symplectic Hamiltonian $G$-variety…

Symplectic Geometry · Mathematics 2020-08-18 Peter Crooks , Markus Röser

Let G be a connected semisimple complex algebraic group and let P be a parabolic subgroup. In this paper we define a new (commutative and associative) product on the cohomology of the homogenous spaces G/P and use this to give a more…

Algebraic Geometry · Mathematics 2016-09-07 Prakash Belkale , Shrawan Kumar

Given a unital partial action $\alpha $ of a group $G$ on a commutative ring $R$ we denote by $ {\bf PicS} _{R^{\alpha}}(R) $ the Picard monoid of the isomorphism classes of partially invertible $R$-bimodules, which are central over the…

Rings and Algebras · Mathematics 2024-11-04 Mikhailo Dokuchaev , Hector Pinedo , Itailma Rocha

We prove a Seidel product formula for the torus-equivariant quantum $K$-theory of a generalized flag variety $G/P.$ This is a natural generalization of the corresponding results by Buch, Chaput, and Perrin for the cominuscule flag…

Algebraic Geometry · Mathematics 2026-03-02 Takeshi Ikeda , Takafumi Kouno , Satoshi Naito

Peterson varieties are special nilpotent Hessenberg varieties that have appeared in the study of quantum cohomology, representation theory, and combinatorics. In type $A$, the Peterson variety $Y$ is a subvariety of the complete flag…

Algebraic Geometry · Mathematics 2022-02-21 Rebecca Goldin , Brent Gorbutt

Lusztig varieties are subvarieties in flag manifolds $G/B$ associated to an element $w$ in the Weyl group $W$ and an element $x$ in $G$, introduced in Lusztig's papers on character sheaves. We study the geometry of these varieties when $x$…

Algebraic Geometry · Mathematics 2026-02-02 Patrick Brosnan , Jaehyun Hong , Donggun Lee

Let $G$ be a complex, connected, reductive algebraic group. In this paper we show analogues of the computations by Borho and MacPherson of the invariants and anti-invariants of the cohomology of the Springer fibres of the cone of nilpotent…

Representation Theory · Mathematics 2007-06-12 J. M. Douglass , G. Roehrle

We consider Hessenberg varieties in the flag variety of $GL_n(\mathbb{C})$ with the property that the corresponding Hessenberg function defines an ad-nilpotent ideal. Each such Hessenberg variety is contained in a Springer fiber. We extend…

Combinatorics · Mathematics 2021-11-09 Caleb Ji , Martha Precup

We define a subclass of Hessenberg varieties called abelian Hessenberg varieties, inspired by the theory of abelian ideals in a Lie algebra developed by Kostant and Peterson. We give an inductive formula for the $S_n$-representation on the…

Combinatorics · Mathematics 2017-12-27 Megumi Harada , Martha Precup

We describe the second cohomology of a regular semisimple Hessenberg variety by generators and relations explicitly in terms of GKM theory. The cohomology of a regular semisimple Hessenberg variety becomes a module of a symmetric group…

Algebraic Geometry · Mathematics 2022-03-23 Anton Ayzenberg , Mikiya Masuda , Takashi Sato