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Related papers: Real structures on nilpotent orbit closures

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In this paper we shall study symplectic resolutions of a nilpotent orbit closure of a complex simple Lie algebra \g. We shall introduce an equivalence relation in the set of parabolic subgroups of $G$ in terms of marked Dynkin diagrams. We…

Algebraic Geometry · Mathematics 2007-05-23 Yoshinori Namikawa

Let $G$ be a simple simply-connected algebraic group over an algebraically closed field $k$ of characteristic $p>0$ with $\mathfrak{g}={\rm Lie}(G)$. We discuss various properties of nilpotent orbits in $\mathfrak{g}$, which have previously…

Representation Theory · Mathematics 2016-04-13 Alexander Premet , David I. Stewart

We continue the study of the distribution of closed geodesics on nilmanifolds constructed from a simply connected 2-step nilpotent Lie group with a left invariant metric and a lattice. We consider a Lie group with an associated 2-step…

Differential Geometry · Mathematics 2007-05-23 Rachelle DeCoste

In general, a nilpotent orbit closure in a complex simple Lie algebra \g, does not have a crepant resolution. But, it always has a Q-factorial terminalization by the minimal model program. According to B. Fu, a nilpotent orbit closure has a…

Algebraic Geometry · Mathematics 2009-08-11 Yoshinori Namikawa

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

Let $G$ be the complex exceptional Lie group of type $G_2$. Among the five nilpotent orbits in its Lie algebra $\mathfrak{g}$, only the 8-dimensional orbit $\mathcal{O}_8$ has non-normal orbit closure $\bar{\mathcal{O}_8}$. In this short…

Representation Theory · Mathematics 2016-10-03 Kayue Daniel Wong

First, I construct an isomorphism between the categories of (topological) groups of nilpotency class 2 with 2-divisible center and (topological) Lie rings of nilpotency class 2 with 2-divisible center. That isomorphism allows us to…

Representation Theory · Mathematics 2007-05-23 Aleksandrs Mihailovs

We introduce post-Lie algebra structures on pairs of Lie algebras $(\Lg,\Ln)$ defined on a fixed vector space $V$. Special cases are LR-structures and pre-Lie algebra structures on Lie algebras. We show that post-Lie algebra structures…

Rings and Algebras · Mathematics 2011-09-02 Dietrich Burde , Karel Dekimpe , Kim Vercammen

In this work we introduce an obstruction for the existence of symplectic structures on nilpotent Lie algebras. Indeed, a necessary condition is presented in terms of the cohomology of the Lie algebra. Using this obstruction we obtain both…

Rings and Algebras · Mathematics 2014-09-25 Viviana J. del Barco

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

We prove that a conical symplectic variety with maximal weight 1 is isomorphic to one of the following: (i) an affine space with the standard symplectic form (ii) a nilpotent orbit closure of a complex semisimple Lie algebra with the…

Algebraic Geometry · Mathematics 2022-07-28 Yoshinori Namikawa

In this paper we construct a deformation quantization of the algebra of polynomials of an arbitrary (regular and non regular) coadjoint orbit of a compact semisimple Lie group. The deformed algebra is given as a quotient of the enveloping…

Quantum Algebra · Mathematics 2007-05-23 M. A. Lledo

Using the notion of existentially closed structures, we obtain embedding theorems for groups and Lie algebras. We also prove the existence of some groups and Lie algebras with prescribed properties.

Group Theory · Mathematics 2014-05-07 M. Shahryari

The aim of this paper is to study the natural action of the real symplectic group, $\operatorname{Sp}(4, \mathbb{R})$, on the algebraic set of $4$-dimensional Lie algebras admitting symplectic structures and to give a complete…

Representation Theory · Mathematics 2023-03-23 Edison Alberto Fernández-Culma , Nadina Elizabeth Rojas

We consider continuous extensions of minimal rotations on a locally connected compact group X by arbitrary locally compact Lie groups and prove regularity (i.e. the existence of orbit closures which project onto the whole basis X) in…

Dynamical Systems · Mathematics 2008-04-17 Ulrich Haboeck , Vyacheslav Kulagin

We prove that for any two projective symplectic resolutions $Z_1$ and $Z_2$ for a nilpotent orbit closure in a complex simple Lie algebra of classical type, then $Z_1$ is deformation equivalen to $Z_2$.

Algebraic Geometry · Mathematics 2007-05-23 Baohua Fu

Let $\g$ be simple Lie algebra. We give a conceptual proof for the fact that the nilpotent orbits of height 3 are spherical. It is shown that if the highest root of $\g$ is fundamental, then $\g$ has a specific nilpotent orbit of height 3.…

Algebraic Geometry · Mathematics 2007-05-23 Dmitri I. Panyushev

We organize the nilpotent orbits in the exceptional complex Lie algebras into series using the triality model and show that within each series the dimension of the orbit is a linear function of the natural parameter a=1,2,4,8, respectively…

Algebraic Geometry · Mathematics 2007-05-23 J. M. Landsberg , L. Manivel , B. W. Westbury

We investigate the existence of left-invariant closed G$_2$-structures on seven-dimensional non-solvable Lie groups, providing the first examples of this type. When the Lie algebra has trivial Levi decomposition, we show that such a…

Differential Geometry · Mathematics 2025-01-03 Anna Fino , Alberto Raffero

In this article, we study adjoint orbits of the Jacobi group, and in particular describe nilpotent orbits explicitely.

Algebraic Geometry · Mathematics 2017-06-14 Yong-Jae Kwon , Jae-Hyun Yang