{ "id": "0704.1367", "version": "v1", "published": "2007-04-11T08:29:44.000Z", "updated": "2007-04-11T08:29:44.000Z", "title": "On families of rational curves in the Hilbert square of a surface (with an Appendix by Edoardo Sernesi)", "authors": [ "Flaminio Flamini", "Andreas Leopold Knutsen", "Gianluca Pacienza", "Edoardo Sernesi" ], "comment": "Submitted preprint. Paper 1: On families of rational curves in the Hilbert square of a surface (with an Appendix by Edoardo Sernesi). Authors: Flaminio Flamini, Andreas Leopold Knutsen and Gianluca Pacienza. Pages: 1 -- 34. Figures: 1. Paper 2: Partial desingularizations of families of nodal curves. Author: Edoardo Sernesi. Pages: 35--37", "categories": [ "math.AG" ], "abstract": "Under natural hypotheses we give an upper bound on the dimension of families of singular curves with hyperelliptic normalizations on a surface S with p_g(S) >0 via the study of the associated families of rational curves in Hilb^2(S). We use this result to prove the existence of nodal curves of geometric genus 3 with hyperelliptic normalizations, on a general K3 surface, thus obtaining specific 2-dimensional families of rational curves in its Hilbert square. We describe two infinite series of examples of general, primitively polarized K3's such that their Hilbert squares contain a IP^2 or a threefold birational to a IP^1-bundle over a K3. We discuss some consequences on the Mori cone of the Hilbert square of a general K3.", "revisions": [ { "version": "v1", "updated": "2007-04-11T08:29:44.000Z" } ], "analyses": { "subjects": [ "14H10", "14H51", "14J28", "14C05", "14C25", "14D15", "14E30" ], "keywords": [ "rational curves", "edoardo sernesi", "hyperelliptic normalizations", "general k3 surface", "hilbert squares contain" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007arXiv0704.1367F" } } }