{ "id": "1604.07743", "version": "v1", "published": "2016-04-26T16:27:30.000Z", "updated": "2016-04-26T16:27:30.000Z", "title": "Saturation and solvability in abstract elementary classes with amalgamation", "authors": [ "Sebastien Vasey" ], "comment": "23 pages", "categories": [ "math.LO" ], "abstract": "$\\mathbf{Theorem.}$ Let $K$ be an abstract elementary class (AEC) with amalgamation and no maximal models. Let $\\lambda > \\text{LS} (K)$. If $K$ is categorical in $\\lambda$, then the model of cardinality $\\lambda$ is Galois-saturated. This answers a question asked independently by Baldwin and Shelah. We deduce several corollaries: $K$ has a unique limit model in each cardinal below $\\lambda$, (when $\\lambda$ is big-enough) $K$ is weakly tame below $\\lambda$, and the thresholds of several existing categoricity transfers can be improved. We also prove a downward transfer of solvability (a version of superstability introduced by Shelah): $\\mathbf{Corollary.}$ Let $K$ be an AEC with amalgamation and no maximal models. Let $\\lambda > \\mu > \\text{LS} (K)$. If $K$ is solvable in $\\lambda$, then $K$ is solvable in $\\mu$.", "revisions": [ { "version": "v1", "updated": "2016-04-26T16:27:30.000Z" } ], "analyses": { "subjects": [ "03C48", "03C45", "03C52", "03C55" ], "keywords": [ "abstract elementary class", "amalgamation", "solvability", "maximal models", "saturation" ], "note": { "typesetting": "TeX", "pages": 23, "language": "en", "license": "arXiv", "status": "editable" } } }