{ "id": "0803.3008", "version": "v2", "published": "2008-03-20T15:20:49.000Z", "updated": "2008-03-26T18:45:08.000Z", "title": "A characterization of surfaces whose universal cover is the bidisk", "authors": [ "Fabrizio Catanese", "Marco Franciosi" ], "comment": "12 pages, references added", "categories": [ "math.AG", "math.CV" ], "abstract": "We show that the universal cover of a compact complex surface $X$ is the bidisk $\\HH \\times \\HH$, or $X$ is biholomorphic to $\\PP^1 \\times \\PP^1$, if and only if $K_X^2 > 0$ and there exists an invertible sheaf $\\eta$ such that $\\eta^2\\cong \\hol_X$ and $H^0(X, S^2\\Omega^1_X (-K_X) \\otimes \\eta) \\neq 0$. The two cases are distinguished by the second plurigenus, $P_2(X)\\geq 2$ in the former case, $P_2(X)= 0$ in the latter. We also discuss related questions.", "revisions": [ { "version": "v2", "updated": "2008-03-26T18:45:08.000Z" } ], "analyses": { "subjects": [ "14J25", "14J29" ], "keywords": [ "universal cover", "characterization", "compact complex surface", "second plurigenus" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2008arXiv0803.3008C" } } }