{ "id": "1007.5036", "version": "v1", "published": "2010-07-28T17:27:00.000Z", "updated": "2010-07-28T17:27:00.000Z", "title": "Involutions on surfaces with $p_g=q=0$ and $K^2=3$", "authors": [ "Carlos Rito" ], "comment": "13 pages", "categories": [ "math.AG" ], "abstract": "We study surfaces of general type $S$ with $p_g=0$ and $K^2=3$ having an involution $i$ such that the bicanonical map of $S$ is not composed with $i$. It is shown that, if $S/i$ is not rational, then $S/i$ is birational to an Enriques surface or it has Kodaira dimension $1$ and the possibilities for the ramification divisor of the covering map $S\\rightarrow S/i$ are described. We also show that these two cases do occur, providing an example. In this example $S$ has a hyperelliptic fibration of genus $3$ and the bicanonical map of $S$ is of degree $2$ onto a rational surface.", "revisions": [ { "version": "v1", "updated": "2010-07-28T17:27:00.000Z" } ], "analyses": { "subjects": [ "14J29" ], "keywords": [ "involution", "bicanonical map", "enriques surface", "general type", "rational surface" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1007.5036R" } } }