The Decomposition Theorem and the Intersection Cohomology of Quotients in Algebraic Geometry
نویسنده
چکیده
Suppose a connected reductive complex algebraic group G acts linearly on a complex projective variety X. We prove that if 1→ N → G→ H → 1 is a short exact sequence of connected reductive groups and X the open set of semistable points for the action of N on X then IH H (X/N) is a direct summand of IH G (X). The inclusion is provided by the decomposition theorem and certain resolutions of the action allow us to define projections.
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تاریخ انتشار 2000