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4:00 pm Tuesday, January 31, 2012 Algebraic Geometry Seminar: Versal Varieties with a Twistby
Alexander Duncan (UCLA) in HB 227- Let G be a linear algebraic group. Informally, a versal G-torsor is a G-torsor (over a field) from which one can recover any other G-torsor. Versal torsors behave similarly to universal objects, but fail to satisfy certain uniqueness properties. In this talk, I introduce several variations of the notion of versality for a G-variety X. These notions have equivalent formulations as properties of twisted forms of X: existence of k-points, density of k-points, k-unirationality and so on. This is joint work with Zinovy Reichstein.
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