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arXiv 1012.31852010-12-14math.LOmath.CT

内在性的分类方法

A categorical approach to internality

Moshe Kamensky

备注：: 18 pages. Part of the results here previously appeared in arxiv:0908.0604

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摘要：

模型论的内在性提供了一个条件，在这个条件下，一个约简上的模型的自同构自同构群本身就是一个可定义群。在本文中，我们制定了一个范畴类比的条件的内在性，并证明了一个类似的结果在范畴水平上。通过考虑可定义集的范畴，恢复了模型的理论陈述。

英文摘要：

Model theoretic internality provides conditions under which the group of automorphisms of a model over a reduct is itself a definable group. In this paper we formulate a categorical analogue of the condition of internality, and prove an analogous result on the categorical level. The model theoretic statement is recovered by considering the category of definable sets.

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