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Related papers: Paving Hessenberg varietes by affines

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We decategorify the Heisenberg 2-category of Gyenge-Koppensteiner-Logvinenko using Hochschild homology. We use this to generalise the Heisenberg algebra action of Grojnowski and Nakajima to all smooth and proper noncommutative varieties in…

Algebraic Geometry · Mathematics 2025-11-06 Ádám Gyenge , Timothy Logvinenko

This article explores the relationship between Hessenberg varieties associated with semisimple operators with two eigenvalues and orbit closures of a spherical subgroup of the general linear group. We establish the specific conditions under…

Algebraic Geometry · Mathematics 2023-09-13 Mahir Bilen Can , Martha Precup , John Shareshian , Özlem Uğurlu

We study the space $X_h$ of Hermitian matrices having staircase form and the given simple spectrum. There is a natural action of a compact torus on this space. Using generalized Toda flow, we show that $X_h$ is a smooth manifold and its…

Algebraic Topology · Mathematics 2023-02-20 Anton Ayzenberg , Victor Buchstaber

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

In this paper we introduce a certain class of families of Hessenberg varieties arising from Springer theory for symmetric spaces. We study the geometry of those Hessenberg varieties and investigate their monodromy representations in detail…

Algebraic Geometry · Mathematics 2020-06-23 Tsao-Hsien Chen , Kari Vilonen , Ting Xue

In this paper, we construct a canonical grading on bordered Heegaard Floer homology by homotopy classes of nonvanishing vector fields. This grading is a generalization of our construction of an absolute grading on Heegaard Floer homology…

Geometric Topology · Mathematics 2014-03-19 Yang Huang , Vinicius G. B. Ramos

We prove the existence of an affine paving for the three-step flag Hilbert scheme $$ \text{Hilb}^{n, n+1, n+2}(0) := \left\{\mathbb{C}[[x,y]]\supset I_n\supset I_{n+1}\supset I_{n+2}: I_i \,\,\text{ ideals with } \text{dim}_{\mathbb{C}}…

Algebraic Geometry · Mathematics 2016-09-19 Daniele Boccalini

We introduce a new language to describe the geometry of affine Deligne-Lusztig varieties in affine flag varieties. This second part of a two paper series uses this new language, i.e. the double Bruhat graph, to describe certain structure…

Representation Theory · Mathematics 2025-09-10 Felix Schremmer

Given a normal surface singularity (X,0), its link, M is a closed differentiable three dimensional manifold which carries much analytic information. It is an interesting question to ask whether, under suitable analytic and topological…

Algebraic Geometry · Mathematics 2016-01-12 Baldur Sigurðsson

Motivated by the Lawrence-Krammer-Bigelow representations of the classical braid groups, we study the homology of unordered configurations in an orientable genus-$g$ surface with one boundary component, over non-commutative local systems…

Geometric Topology · Mathematics 2025-09-16 Christian Blanchet , Martin Palmer , Awais Shaukat

We formulate a very general conjecture relating the analytical invariants of a normal surface singularity to the Seiberg-Witten invariants of its link provided that the link is a rational homology sphere. As supporting evidence, we…

Algebraic Geometry · Mathematics 2014-11-11 Andras Nemethi , Liviu I Nicolaescu

We use the G-invariant non-degenerate form on the Steinberg module to Frobenius split the cotangent bundle of a flag variety in good prime characteristics. This was previously only known for the general linear group. Applications are a…

Algebraic Geometry · Mathematics 2015-06-26 Shrawan Kumar , Niels Lauritzen , Jesper Funch Thomsen

This article proves a uniform exponential decay estimate for Seiberg-Witten equations on non-compact 4-manifolds with exact symplectic ends of bounded geometry. This is an extension of the analysis for asymptotically flat almost K\"ahler…

Geometric Topology · Mathematics 2021-06-03 Boyu Zhang

After proving that every Schubert variety in the full flag variety of a complex reductive group $G$ is a general Hessenberg variety, we show that not all such Schubert varieties are adjoint Hessenberg varieties. In fact, in types A and C,…

Algebraic Geometry · Mathematics 2021-07-19 Laura Escobar , Martha Precup , John Shareshian

Here we construct spaces of coinvariants for Heisenberg vertex algebras on abelian varieties and show that these globalize to twisted $\mathscr{D}$-modules on the moduli space of abelian varieties. Remarkably, we recover the standard…

Algebraic Geometry · Mathematics 2026-04-02 Nicola Tarasca

We initiate the representation theory of the degenerate affine periplectic Brauer algebra on $n$ strands by constructing its finite-dimensional calibrated representations when $n=2$. We show that any such representation that is…

Representation Theory · Mathematics 2019-05-14 Zajj Daugherty , Iva Halacheva , Mee Seong Im , Emily Norton

We study Kummer varieties attached to 2-coverings of abelian varieties of arbitrary dimension. Over a number field we show that the subgroup of odd order elements of the Brauer group does not obstruct the Hasse principle. Sufficient…

Algebraic Geometry · Mathematics 2017-11-20 Alexei N. Skorobogatov , Yuri G. Zarhin

We prove a conjecture of A. S. Buch concerning the structure constants of the Grothendieck ring of a flag variety with respect to its basis of Schubert structure sheaves. For this, we show that the coefficients in this basis of the…

Algebraic Geometry · Mathematics 2007-05-23 Michel Brion

A smooth projective variety with an action of a torus admits a cell decomposition, called the Bialynicki-Birula decomposition. Singularities of the closures of these cells are not well-known. One of the examples of such closures is a…

Algebraic Geometry · Mathematics 2025-06-27 Jaehyun Hong , Eunjeong Lee , Seonjeong Park

We show how to reconstruct a graded ample Hausdorff groupoid with topologically principal neutrally graded component from the ring structure of its graded Steinberg algebra over any commutative integral domain with 1, together with the…

Rings and Algebras · Mathematics 2020-02-25 Pere Ara , Joan Bosa , Roozbeh Hazrat , Aidan Sims