{ "id": "math/0111052", "version": "v1", "published": "2001-11-06T16:57:25.000Z", "updated": "2001-11-06T16:57:25.000Z", "title": "On the Canonical Ring of Covers of Surfaces of Minimal Degree", "authors": [ "Francisco J. Gallego", "B. P. Purnaprajna" ], "comment": "22 pages, amstex", "categories": [ "math.AG" ], "abstract": "Let f be a generically finite morphism from X to Y. The purpose of this paper is to show how the O_Y algebra structure on the push forward of O_X controls algebro-geometric aspects of X like the ring generation of graded rings associated to X and the very ampleness of line bundles on X. As the main application of this we prove some new results for certain regular surfaces X of general type. Precisely, we find the degrees of the generators of the canonical ring of X when the canonical morphism of X is a finite cover of a surface of minimal degree. These results complement results of Ciliberto [Ci] and Green [G]. The techniques of this paper also yield different proofs of some earlier results, such as Noether's theorem for certain kinds of curves and some results on Calabi-Yau threefolds that had appeared in [GP2].", "revisions": [ { "version": "v1", "updated": "2001-11-06T16:57:25.000Z" } ], "analyses": { "subjects": [ "14J29", "14J32" ], "keywords": [ "minimal degree", "canonical ring", "controls algebro-geometric aspects", "results complement results", "calabi-yau threefolds" ], "note": { "typesetting": "AMS-TeX", "pages": 22, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2001math.....11052G" } } }