Relativized Galois groups of first order theories over a hyperimaginary

Hyoyoon Lee; Junguk Lee

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arXiv · 2402.11619

Relativized Galois groups of first order theories over a hyperimaginary

Hyoyoon Lee·Junguk Lee

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Abstract

We study relativized Lascar groups, which are formed by relativizing Lascar groups to the solution set of a partial type $Σ$. We introduce the notion of a Lascar tuple for $Σ$ and by considering the space of types over a Lascar tuple for $Σ$, the topology for a relativized Lascar group is (re-)defined and some fundamental facts about the Galois groups of first-order theories are generalized to the relativized context. In particular, we prove that any closed subgroup of a relativized Lascar group corresponds to a stabilizer of a bounded hyperimaginary having at least one representative in the solution set of the given partial type $Σ$. Using this, we find the correspondence between subgroups of the relativized Lascar group and the relativized strong types.

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BibTeX RIS

Hyoyoon Lee, Junguk Lee. 2024-08-10. Relativized Galois groups of first order theories over a hyperimaginary. https://arxiv.org/abs/2402.11619

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