Approximating classifying spaces by smooth projective varieties

dc.creatorEkedahl, Torsten
dc.date2009-05-11
dc.date.accessioned2026-07-07T13:13:38Z
dc.date.available2026-07-07T13:13:38Z
dc.descriptionWe prove that for every reductive algebraic group $H$ with centre of positive dimension and every integer $K$ there is a smooth and projective variety $X$ and an algebraic $H$-torsor $P \to X$ such that the classifying map $X \to \Bclass H$ induces an isomorphism in cohomology in degrees $\le K$. This is then applied to show that if $G$ is a connected non-special group there is a $G$-torsor $P \to X$ for which we do not have $[P]=[G][X]$ in the (completion of the) Grothendieck ring of varieties.
dc.description9 pages
dc.identifierhttps://arxiv.org/abs/0905.1538
dc.identifierhttp://arxiv.org/abs/0905.1538
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/229954
dc.subjectAlgebraic Geometry
dc.subjectAlgebraic Topology
dc.subject55R40; 14L24, 14F25
dc.titleApproximating classifying spaces by smooth projective varieties
dc.typetext

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