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Related papers: Fibres de Springer et jacobiennes compactifiees

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The flag variety of a complex reductive linear algebraic group G is by definition the quotient G/B by a Borel subgroup. It can be regarded as the set of Borel subalgebras of Lie(G). Given a nilpotent element e in Lie(G), one calls Springer…

Representation Theory · Mathematics 2014-05-20 Lucas Fresse

We survey the theory of the compactified Jacobian associated to a singular curve. We focus on describing low genus examples using the Abel map.

Algebraic Geometry · Mathematics 2015-09-01 Jesse Leo Kass

We construct a weak representation of the category of framed affine tangles on a disjoint union of triangulated categories ${\mathcal D}_{2n}$. The categories we use are that of coherent sheaves on Springer fibers over a nilpotent element…

Algebraic Geometry · Mathematics 2016-02-09 Rina Anno

We study the structure of Jacobians of geometrically reduced curves over arbitrary (i. e., not necessarily perfect) fields. We show that, while such a group scheme cannot in general be decomposed into an affine and an Abelian part as over…

Algebraic Geometry · Mathematics 2023-10-30 Otto Overkamp

We introduce parabolic multiplicative affine Springer fibers, which resemble the admissible union of affine Deligne Lusztig varieties in the affine flag variety. We also study their global counterparts called parabolic multiplicative…

Algebraic Geometry · Mathematics 2024-12-13 Marielle Ong

We prove that there exist some stacks, representable over the stack of stable curves, having the following universal property with respect to N\'eron models of Jacobians. For every one-parameter family of stable curves, with regular total…

Algebraic Geometry · Mathematics 2007-05-23 Lucia Caporaso

We study the interaction between Fourier-Mukai transforms and perverse filtrations for a certain class of dualizable abelian fibrations. Multiplicativity of the perverse filtration and the "Perverse $\supset$ Chern" phenomenon for these…

Algebraic Geometry · Mathematics 2025-10-09 Davesh Maulik , Junliang Shen , Qizheng Yin

The purpose of this paper is to study the cohomology rings of universal compactified Jacobians. Over the moduli space $\overline{\mathcal{M}}_{g,n}$ of Deligne-Mumford stable marked curves with $n\geq 1$, on the one hand we show that the…

Algebraic Geometry · Mathematics 2025-10-29 Younghan Bae , Davesh Maulik , Junliang Shen , Qizheng Yin

We construct modular compactifications of the universal Jacobian stack over the moduli stack of reduced curves with marked points depending on stability parameters obtained out of fixing a vector bundle on the universal curve. When…

Algebraic Geometry · Mathematics 2016-09-16 Margarida Melo

We give characterizations of affine transformations and affine vector fields in terms of the spray. By utilizing the Jacobi type equation that characterizes affine vector fields, we prove some rigidity theorems of affine vector fields on…

Differential Geometry · Mathematics 2018-11-26 Libing Huang , Qiong Xue

We look at the decomposition of the compactified jacobian of a singular curve into components and discuss some examples.

alg-geom · Mathematics 2008-02-03 Jyotsna Gokhale

For any connected reductive group $G$ over $\mathbb{C}$, we revisit Goresky-Kottwitz-MacPherson's description of the torus equivariant Borel-Moore homology of affine Springer fibers $\mathrm{Sp}_\gamma\subset \mathrm{Gr}_G$, where…

Algebraic Geometry · Mathematics 2019-09-10 Oscar Kivinen

Let $k$ be a number field and $X$ a smooth integral affine variety equipped with a morphism $f : X \to A^1_k$ to the affine line. Assume that all fibres of $f$ are split, for instance that they are geometrically integral. Assume that the…

Number Theory · Mathematics 2013-07-17 Jean-Louis Colliot-Thélène , David Harari

We prove a general result on the existence of irreducible symplectic compactifications of non-compact Lagrangian fibrations. As an application, we show that the relative Jacobian fibration of cubic fivefolds containing a fixed cubic…

Algebraic Geometry · Mathematics 2025-05-06 Yuchen Liu , Zhiyu Liu , Chenyang Xu

We study extension properties for morphisms of stacks of bundles for group algebraic spaces. Applications are a short proof of the classification of bundles on the projective line for smooth geometrically reductive groups and the existence…

Algebraic Geometry · Mathematics 2024-09-05 Torsten Wedhorn

Given a semisimple element in the loop Lie algebra of a reductive group, we construct a quasi-coherent sheaf on a partial resolution of the trigonometric commuting variety of the Langlands dual group. The construction uses affine Springer…

Algebraic Geometry · Mathematics 2025-02-04 Eugene Gorsky , Oscar Kivinen , Alexei Oblomkov

We give an explicit description of the irreducible components of two-row Springer fibers for all classical types using cup diagrams. Cup diagrams can be used to label the irreducible components of two-row Springer fibers. Given a cup…

Representation Theory · Mathematics 2022-02-01 Mee Seong Im , Chun-Ju Lai , Arik Wilbert

We consider the question whether a real threefold X fibred into quadric surfaces over the real projective line is stably rational (over R) if the topological space X(R) is connected. We give a counterexample. When all geometric fibres are…

Algebraic Geometry · Mathematics 2026-02-11 Jean-Louis Colliot-Thélène , Alena Pirutka

We describe the irreducible components of Springer fibers for hook and two-row nilpotent elements of gl_n(C) as iterated bundles of flag manifolds and Grassmannians. We then relate the topology (in particular, the intersection homology…

Representation Theory · Mathematics 2007-05-23 Francis Fung

We give some properties (cancellation, representability, stratification) of the sheaf R^i f_* G for an affine relative curve f:U -> S admitting a smooth compactification and G a solvable group.

Algebraic Geometry · Mathematics 2009-03-17 Sylvain Maugeais