{ "id": "math/0607476", "version": "v4", "published": "2006-07-19T19:47:59.000Z", "updated": "2008-03-07T12:03:52.000Z", "title": "J-invariant of linear algebraic groups", "authors": [ "Victor Petrov", "Nikita Semenov", "Kirill Zainoulline" ], "comment": "The paper containes 39 pages and uses XYPIC package", "journal": "Ann. Sci. Ecole Norm. Sup. (4) 41 (2008), no.6, 1023-1053.", "categories": [ "math.AG" ], "abstract": "Let G be a linear algebraic group over a field F and X be a projective homogeneous G-variety such that G splits over the function field of X. In the present paper we introduce an invariant of G called J-invariant which characterizes the motivic behaviour of X. This generalizes the respective notion invented by A. Vishik in the context of quadratic forms. As a main application we obtain a uniform proof of all known motivic decompositions of generically split projective homogeneous varieties (Severi-Brauer varieties, Pfister quadrics, maximal orthogonal Grassmannians, G2- and F4-varieties) as well as provide new examples (exceptional varieties of types E6, E7 and E8). We also discuss relations with torsion indices, canonical dimensions and cohomological invariants of the group G.", "revisions": [ { "version": "v4", "updated": "2008-03-07T12:03:52.000Z" } ], "analyses": { "subjects": [ "14C15", "14M15" ], "keywords": [ "linear algebraic group", "j-invariant", "maximal orthogonal grassmannians", "motivic decompositions", "function field" ], "tags": [ "research tool", "journal article" ], "note": { "typesetting": "TeX", "pages": 39, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......7476P" } } }