{ "id": "2404.15066", "version": "v1", "published": "2024-04-23T14:13:35.000Z", "updated": "2024-04-23T14:13:35.000Z", "title": "Maximal Brill-Noether loci via degenerations and double covers", "authors": [ "Andrei Bud", "Richard Haburcak" ], "comment": "16 pages, comments welcome! MPIM-Bonn-2024", "categories": [ "math.AG" ], "abstract": "Using limit linear series on chains of curves, we show that closures of certain Brill-Noether loci contain a product of pointed Brill-Noether loci of small codimension. As a result, we obtain new non-containments of Brill-Noether loci, in particular that dimensionally expected non-containments hold for expected maximal Brill-Noether loci. Using these degenerations, we also give a new proof that Brill-Noether loci with expected codimension $-\\rho\\leq \\lceil g/2 \\rceil$ have a component of the expected dimension. Additionally, we obtain new non-containments of Brill-Noether loci by considering the locus of the source curves of unramified double covers.", "revisions": [ { "version": "v1", "updated": "2024-04-23T14:13:35.000Z" } ], "analyses": { "subjects": [ "14H51", "14H10" ], "keywords": [ "double covers", "degenerations", "limit linear series", "expected maximal brill-noether loci", "brill-noether loci contain" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable" } } }