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arXiv 0904.2841math.RT
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经典根系的正交子集与幂幺群的余伴随轨道

Orthogonal subsets of classical root systems and coadjoint orbits of unipotent groups

Mikhail V. Ignatyev

摘要:

设$Φ$是一个典型的根系,$k$是一个具有足够大特征的域。设$G$是$k$上的典型群,其根系为$Φ$,$U$是它的极大幂幺子群,$\mathfrak{u}$是$U$的李代数.令$D$是$Φ$的正交子集,$Ω$是与$D$相关联的$U$的余伴随轨道。我们在$Ω$上构造了$\mathfrak{u}$的标准型极化.我们还找到了$Ω$的维数与$Φ$的Weyl群的关系。作为推论,我们确定了有限域$k$情形下群$U$的不可约复表示的所有可能维数。

英文摘要:

Let $Φ$ be a classical root system and $k$ be a field of sufficiently large characteristic. Let $G$ be the classical group over $k$ with the root system $Φ$, $U$ be its maximal unipotent subgroup and $\mathfrak{u}$ be the Lie algebra of $U$. Let $D$ be an orthogonal subset of $Φ$ and $Ω$ be a coadjoint orbit of $U$ associated with $D$. We construct a polarization of $\mathfrak{u}$ at the canonical form on $Ω$. We also find the dimension of $Ω$ in terms of the Weyl group of $Φ$. As a corollary, we determine all possible dimensions of irreducible complex represenations of the group $U$ for the case of finite field $k$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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