{ "id": "0905.3121", "version": "v1", "published": "2009-05-19T14:57:27.000Z", "updated": "2009-05-19T14:57:27.000Z", "title": "The computation of Stiefel-Whitney classes", "authors": [ "Pierre Guillot" ], "comment": "To appear in Ann. Inst. Fourier", "categories": [ "math.AT" ], "abstract": "The cohomology ring of a finite group, with coefficients in a finite field, can be computed by a machine, as Carlson has showed. Here \"compute\" means to find a presentation in terms of generators and relations, and involves only the underlying (graded) ring. We propose a method to determine some of the extra structure: namely, Stiefel-Whitney classes and Steenrod operations. The calculations are explicitly carried out for about one hundred groups (the results can be consulted on the Internet). Next, we give an application: thanks to the new information gathered, we can in many cases determine which cohomology classes are supported by algebraic varieties.", "revisions": [ { "version": "v1", "updated": "2009-05-19T14:57:27.000Z" } ], "analyses": { "subjects": [ "20J06", "57R20", "65K05", "14C15" ], "keywords": [ "stiefel-whitney classes", "computation", "finite group", "algebraic varieties", "finite field" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0905.3121G" } } }