{ "id": "2402.11619", "version": "v2", "published": "2024-02-18T15:22:31.000Z", "updated": "2024-08-10T02:37:07.000Z", "title": "Relativized Galois groups of first order theories over a hyperimaginary", "authors": [ "Hyoyoon Lee", "Junguk Lee" ], "comment": "19 pages; many omitted proofs are now provided, exposition is improved, half of the last section is rewritten, citations and typos are corrected", "categories": [ "math.LO" ], "abstract": "We study relativized Lascar groups, which are formed by relativizing Lascar groups to the solution set of a partial type $\\Sigma$. We introduce the notion of a Lascar tuple for $\\Sigma$ and by considering the space of types over a Lascar tuple for $\\Sigma$, 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 $\\Sigma$. Using this, we find the correspondence between subgroups of the relativized Lascar group and the relativized strong types.", "revisions": [ { "version": "v2", "updated": "2024-08-10T02:37:07.000Z" } ], "analyses": { "subjects": [ "03C99" ], "keywords": [ "first order theories", "relativized galois groups", "hyperimaginary", "solution set", "partial type" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }