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arXiv 1409.8635math.LO
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伪有限结构与简单性

Pseudofinite structures and simplicity

Dario Garcia, Dugald Macpherson, Charles Steinhorn

摘要:

我们探讨了伪有限维的概念,介绍了由Hrushovski和瓦格纳,对有限结构的无限超积。确定了伪有限维的某些条件,保证基础理论的简单性或超简单性,并且伪有限维的下降相当于分叉。在适当的假设下,证明了测度论条件等价于局部稳定性。许多例子进行了探讨,包括向量空间的有限域视为2-排序有限结构,和同素循环群。连接产品的集合在有限群,特别是字地图,并概括道的代数规律引理指出。

英文摘要:

We explore a notion of pseudofinite dimension, introduced by Hrushovski and Wagner, on an infinite ultraproduct of finite structures. Certain conditions on pseudofinite dimension are identified that guarantee simplicity or supersimplicity of the underlying theory, and that a drop in pseudofinite dimension is equivalent to forking. Under a suitable assumption, a measure-theoretic condition is shown to be equivalent to local stability. Many examples are explored, including vector spaces over finite fields viewed as 2-sorted finite structures, and homocyclic groups. Connections are made to products of sets in finite groups, in particular to word maps, and a generalization of Tao's algebraic regularity lemma is noted.

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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