{ "id": "1704.03392", "version": "v1", "published": "2017-04-11T16:13:58.000Z", "updated": "2017-04-11T16:13:58.000Z", "title": "The complexity of the embeddability between torsion-free abelian groups of uncountable size", "authors": [ "Filippo Calderoni" ], "comment": "14 pages", "categories": [ "math.LO" ], "abstract": "We prove that for every uncountable cardinal $\\kappa$ such that $\\kappa^{<\\kappa}=\\kappa$, the quasi-order of embeddability on the $\\kappa$-space of $\\kappa$-sized graphs Borel reduces to the embeddability on the $\\kappa$-space of $\\kappa$-sized torsion-free abelian groups. Then we use the same techniques to prove that the former Borel reduces to the embeddability on the $\\kappa$-space of $\\kappa$-sized $R$-modules, for every $\\mathbb{S}$-cotorsion-free ring $R$ of cardinality less than the continuum. As a consequence we get that all the previous are complete $\\Sigma^1_1$ quasi-orders.", "revisions": [ { "version": "v1", "updated": "2017-04-11T16:13:58.000Z" } ], "analyses": { "subjects": [ "03E15" ], "keywords": [ "embeddability", "uncountable size", "complexity", "sized torsion-free abelian groups", "sized graphs borel reduces" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }