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arXiv 1406.6928math.CT
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对称幺半范畴范畴的下降、不变量域和一般形式

Descent, fields of invariants and generic forms via symmetric monoidal categories

Ehud Meir

摘要:

设$W$是特征为零的域$K$上的有限维代数结构(例如代数)。利用Deligne的对称幺半范畴理论研究了$W$的形式。我们构造了一个范畴$\mathcal{C}_W$,它产生了一个子域$K_0\subseteq K$,我们称之为$W$的不变量域。此字段将包含在$W$具有表单的$K$的任何子字段中。范畴$\mathcal{C}_W$是$Rep_{\bar{K}}(Aut(W))$的$K_0$ -形式,我们用它来构造交换$K_0$代数$B_W$上的一般形式$\widetilde{W}$(因此$W$的形式恰好是$\widetilde{W}$的特化)。这推广了中心单代数和$H$ -余代数的一般构造。给出了结合代数和$H$ -余代数的一些具体例子。作为应用,我们还解释了如何使用该构造来分类有限维Hopf代数上的双上圈。

英文摘要:

Let $W$ be a finite dimensional algebraic structure (e.g. an algebra) over a field $K$ of characteristic zero. We study forms of $W$ by using Deligne's Theory of symmetric monoidal categories. We construct a category $\mathcal{C}_W$, which gives rise to a subfield $K_0\subseteq K$, which we call the field of invariants of $W$. This field will be contained in any subfield of $K$ over which $W$ has a form. The category $\mathcal{C}_W$ is a $K_0$-form of $Rep_{\bar{K}}(Aut(W))$, and we use it to construct a generic form $\widetilde{W}$ over a commutative $K_0$ algebra $B_W$ (so that forms of $W$ are exactly the specializations of $\widetilde{W}$). This generalizes some generic constructions for central simple algebras and for $H$-comodule algebras. We give some concrete examples arising from associative algebras and $H$-comodule algebras. As an application, we also explain how can one use the construction to classify two-cocycles on some finite dimensional Hopf algebras.

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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