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arXiv · 1507.05054

Equivariant Chow classes of matrix orbit closures

Andrew Berget·Alex Fink
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Abstract

Let $G$ be the product $GL_r(C) \times (C^\times)^n$. We show that the $G$-equivariant Chow class of a $G$ orbit closure in the space of $r$-by-$n$ matrices is determined by a matroid. To do this, we split the natural surjective map from the $G$ equvariant Chow ring of the space of matrices to the torus equivariant Chow ring of the Grassmannian. The splitting takes the class of a Schubert variety to the corresponding factorial Schur polynomial, and also has the property that the class of a subvariety of the Grassmannian is mapped to the class of the closure of those matrices whose row span is in the variety.

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Andrew Berget, Alex Fink. 2015-07-17. Equivariant Chow classes of matrix orbit closures. https://doi.org/10.1007/s00031-016-9406-5

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