{ "id": "1308.0472", "version": "v1", "published": "2013-08-02T11:36:01.000Z", "updated": "2013-08-02T11:36:01.000Z", "title": "Albanese and Picard 1-Motives in Positive Characteristic", "authors": [ "Peter Mannisto" ], "comment": "Comments welcome", "categories": [ "math.AG" ], "abstract": "We define 1-motives of a variety X over a perfect field of positive characteristic which realize the etale cohomology groups of X in dimension and codimension one. This is the analogue in positive characteristic of previous results of Barbieri-Viale and Srinivas, except that we only consider the etale realization but also consider compactly supported cohomology. The dimension-1 case (called the Picard 1-motives) can be done by standard techniques, and indeed this case is probably well known. But the codimension-one case (Albanese 1-motive) requires stronger tools, namely a strong version of de Jong's alterations theorem and some cycle class theory on smooth Deligne-Mumford stacks which may be of independent interest. Unfortunately, we only succeed in defining the Albanese 1-motive for a variety X over an algebraically closed base field, and only up to isogeny. As a corollary to our definition of these 1-motives we deduce some independence of l results when X is a variety over a finite field.", "revisions": [ { "version": "v1", "updated": "2013-08-02T11:36:01.000Z" } ], "analyses": { "subjects": [ "14F20", "14G10" ], "keywords": [ "positive characteristic", "smooth deligne-mumford stacks", "cycle class theory", "jongs alterations theorem", "etale cohomology groups" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1308.0472M" } } }