{ "id": "1007.5364", "version": "v2", "published": "2010-07-30T03:54:20.000Z", "updated": "2012-02-09T14:28:59.000Z", "title": "Reduced Divisors and Embeddings of Tropical Curves", "authors": [ "Omid Amini" ], "comment": "Final version (to appear in Trans. Amer. Math. Soc.), 29 pages, 2 figures", "categories": [ "math.CO", "math.AG" ], "abstract": "Given a divisor $D$ on a tropical curve $\\Gamma$, we show that reduced divisors define an integral affine map from the tropical curve to the complete linear system $|D|$. This is done by providing an explicit description of the behavior of reduced divisors under infinitesimal modifications of the base point. We consider the cases where the reduced-divisor map defines an embedding of the curve into the linear system, and in this way, classify all the tropical curves with a very ample canonical divisor. As an application of the reduced-divisor map, we show the existence of Weierstrass points on tropical curves of genus at least two and present a simpler proof of a theorem of Luo on rank-determining sets of points. We also discuss the classical analogue of the (tropical) reduced-divisor map: For a smooth projective curve $C$ and a divisor $D$ of non-negative rank on $C$, reduced divisors equivalent to $D$ define a morphism from $C$ to the complete linear system $|D|$, which is described in terms of Wronskians.", "revisions": [ { "version": "v2", "updated": "2012-02-09T14:28:59.000Z" } ], "analyses": { "keywords": [ "tropical curve", "complete linear system", "integral affine map", "reduced-divisor map defines", "explicit description" ], "note": { "typesetting": "TeX", "pages": 29, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1007.5364A" } } }