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The minimal degeneration singularities in the affine Grassmannians

Anton Malkin·Viktor Ostrik·Maxim Vybornov
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Abstract

The minimal degeneration singularities in the affine Grassmannians of simple simply-laced algebraic groups are determined to be either Kleinian singularities of type A, or closures of minimal orbits in nilpotent cones. The singularities for non-simply-laced types are studied by intersection cohomology and equivariant Chow group methods.

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Anton Malkin, Viktor Ostrik, Maxim Vybornov. 2003-05-06. The minimal degeneration singularities in the affine Grassmannians. https://arxiv.org/abs/math/0305095

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