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Related papers: Normality of nilpotent varieties in $E_6$

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This is a survey article prepared for the submission to "Handbook of moduli". The following topics are discussed: (i) Basic facts and examples of resolutions for nilpotent orbit (ii) Q-factorial terminalizations of nilpotent orbit closures…

Algebraic Geometry · Mathematics 2013-06-25 Yoshinori Namikawa

Let R be a ring with the set of nilpotents Nil(R). We prove that the following are equivalent: (i) Nil(R) is additively closed, (ii) Nil(R) is multiplicatively closed and R satisfies Koethe's conjecture, (iii) Nil(R) is closed under the…

Rings and Algebras · Mathematics 2016-07-11 Janez Šter

We show that the numbers of nilpotent coadjoint orbits in the dual of exceptional Lie algebra $G_2$ in characteristic $3$ and in the dual of exceptional Lie algebra $F_4$ in characteristic $2$ are finite. We determine the closure relation…

Representation Theory · Mathematics 2018-05-25 Ting Xue

We give a simple description of the closure of the nilpotent orbits appearing as associated varieties of admissible affine vertex algebras in terms of primitive ideals.

Representation Theory · Mathematics 2022-07-15 Tomoyuki Arakawa , Jethro van Ekeren , Anne Moreau

Let G be a reductive algebraic group in classical types A, B, D and e be an element of its Lie algebra with Z its centraliser in G for the adjoint action. We suppose that e identifies with an nilpotent matrix of order two, which guarantees…

Algebraic Geometry · Mathematics 2024-05-14 Simon Jacques

This paper is about nilpotent orbits of reductive groups over local non-Archimedean fields. In this paper we will try to identify for which groups there are only finitely many nilpotent orbits, for which groups the nilpotent orbits are…

Representation Theory · Mathematics 2015-09-14 Julius Witte

The condition of nilpotency is studied in the general linear Lie algebra $\mathfrak{gl}_{n}(\mathbb{K})$ and the symplectic Lie algebra $\mathfrak{sp}_{2m}(\mathbb{K})$ over an algebraically closed field of characteristic 0. In particular,…

Algebraic Geometry · Mathematics 2014-03-14 Samuel Reid

We prove some results on the nilpotent orbit theorem for complex variation of Hodge structures.

Algebraic Geometry · Mathematics 2023-11-01 Ya Deng

We consider the conjugation-action of an arbitrary upper-block parabolic subgroup of GL_n(C) on the variety of x-nilpotent complex matrices. We obtain a criterion as to whether the action admits a finite number of orbits and specify a…

Representation Theory · Mathematics 2012-07-19 Magdalena Boos

We give a full classification of 6-dimensional nilpotent Lie algebras over an arbitrary field, including fields that are not algebraically closed and fields of characteristic~2. To achieve the classification we use the action of the…

Rings and Algebras · Mathematics 2020-06-26 Serena Cicalo , Willem A de Graaf , Csaba Schneider

This paper is a continuation of arXiv:1201.1102. We investigate the orbit closures for the class of representations of simple algebraic groups associated to various gradings on the simple Lie algebra of type $E_7$. The methods for…

Representation Theory · Mathematics 2013-02-05 Witold Kraskiewicz , Jerzy Weyman

A nilpotent orbit $O$ of a complex semisimple Lie algebra $\mathfrak{g}$ has finite fundamental group. Associated with an etale cover of $O$, we have a finite cover of the closure $\bar{O}$ of $O$. In this article we consider the finite…

Algebraic Geometry · Mathematics 2022-07-27 Yoshinori Namikawa

Let G be a simple algebraic group over an algebraically closed field with Lie algebra g. Then the orbits of nilpotent elements of g under the adjoint action of G have been classified. We describe a simple algorithm for finding a…

Group Theory · Mathematics 2011-11-09 Willem de Graaf

We treat the topic of the closures of the nilpotent orbits of the Lie algebras of Exceptional groups through their descriptions as moduli spaces, in terms of Hilbert series and the highest weight generating functions for their…

High Energy Physics - Theory · Physics 2018-01-17 Amihay Hanany , Rudolph Kalveks

We prove that any symplectic resolution of the closure of a nilpotent orbit in a semi-simple complex Lie algebra is isomorphic to the collapsing of the cotangent bundle of a projective homogenous variety. Then we give a complete…

Algebraic Geometry · Mathematics 2015-06-26 Baohua Fu

There are normal sub-blocks of nilpotent blocks which are NOT nilpotent or, equivalently, nilpotent extensions of non-nilpotent blocks. In this paper we determine the source algebra structure of the non-nilpotent blocks involved in these…

Group Theory · Mathematics 2010-04-12 Lluis Puig

In the case of complex symplectic and orthogonal groups, we find $(\mathfrak{g}, K)-$modules with the property that their $K-$structure matches the structure of regular functions on the closures of nilpotent orbits. This establishes a…

Representation Theory · Mathematics 2022-05-17 Dan Barbasch , Kayue Daniel Wong

Let $G$ be a quasi-simple algebraic group defined over an algebraically closed field $k$ and $B$ a Borel subgroup of $G$ acting on the nilradical $\mathfrak{n}$ of its Lie algebra $\mathfrak{b}$ via the Adjoint representation. It is known…

Group Theory · Mathematics 2019-02-06 Madeleine Burkhart , David Vella

Let A be a finitely generated associative algebra over an algebraically closed field. We characterize the finite dimensional modules over A whose orbit closures are regular varieties.

Algebraic Geometry · Mathematics 2007-05-23 Nguyen Quang Loc , Grzegorz Zwara

We prove that the orbit closure of the determinant is not normal. A similar result is obtained for the orbit closure of the permanent multiplied by a power of a linear form.

Algebraic Geometry · Mathematics 2010-07-13 Shrawan Kumar