{ "id": "1609.02091", "version": "v1", "published": "2016-09-07T17:50:11.000Z", "updated": "2016-09-07T17:50:11.000Z", "title": "A note on Brill--Noether existence for graphs of low genus", "authors": [ "Stanislav Atanasov", "Dhruv Ranganathan" ], "comment": "19 pages, 36 TikZ figures. Comments are welcome!", "categories": [ "math.AG", "math.CO" ], "abstract": "In an influential 2008 paper, Baker proposed a number of conjectures relating the divisor theory of algebraic curves with an analogous combinatorial theory on finite graphs. In this note, we examine Baker's Brill--Noether existence conjecture for special divisors. For $g\\leq 5$ and $\\rho(g,r,d)$ non-negative, every graph of genus $g$ is shown to admit a divisor of rank $r$ and degree at most $d$. Moreover, the conjecture is shown to hold in rank $1$ for a number of families of highly connected combinatorial types of graphs of arbitrarily high genus. In the relevant genera, our arguments give the first combinatorial proof of the Brill--Noether existence theorem for metric graphs, giving a partial answer to a related question of Baker.", "revisions": [ { "version": "v1", "updated": "2016-09-07T17:50:11.000Z" } ], "analyses": { "subjects": [ "14T05" ], "keywords": [ "low genus", "bakers brill-noether existence conjecture", "first combinatorial proof", "brill-noether existence theorem", "analogous combinatorial theory" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }