{ "id": "2005.13372", "version": "v1", "published": "2020-05-27T14:06:42.000Z", "updated": "2020-05-27T14:06:42.000Z", "title": "Galois subspaces for smooth projective curves", "authors": [ "Robert Auffarth", "Sebastián Rahausen" ], "comment": "16 pages including appendix. Comments are welcome!", "categories": [ "math.AG" ], "abstract": "Given an embedding of a smooth projective curve $X$ of genus $g\\geq1$ into $\\mathbb{P}^N$, we study the locus of linear subspaces of $\\mathbb{P}^N$ of codimension 2 such that projection from said subspace, composed with the embedding, gives a Galois morphism $X\\to\\mathbb{P}^1$. For genus $g\\geq2$ we prove that this locus is a smooth projective variety with components isomorphic to projective spaces. If $g=1$ and the embedding is given by a complete linear system, we prove that this locus is also a smooth projective variety whose positive-dimensional components are isomorphic to projective bundles over \\'etale quotients of the elliptic curve, and we describe these components explicitly.", "revisions": [ { "version": "v1", "updated": "2020-05-27T14:06:42.000Z" } ], "analyses": { "keywords": [ "smooth projective curve", "galois subspaces", "smooth projective variety", "complete linear system", "components isomorphic" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable" } } }