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Birational geometry for the covering of a nilpotent orbit closure

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Let \({\mathfrak {g}}\) be a complex classical simple Lie algebra and let O be a nilpotent orbit of \({\mathfrak {g}}\). The fundamental group \(\pi _1(O)\) is finite. Take the universal covering \(\pi ^0: X^0 \rightarrow O\). Then \(\pi ^0\) extends to a finite cover \(\pi : X \rightarrow {\bar{O}}\). By using the Kirillov–Kostant form \(\omega _{KK}\) on O, the normal affine variety X becomes a conical symplectic variety. In this article we give an explicit construction of a Q-factorial terminalization of X.

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Namikawa, Y. Birational geometry for the covering of a nilpotent orbit closure. Sel. Math. New Ser. 28, 75 (2022). https://doi.org/10.1007/s00029-022-00790-2

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