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arXiv · hep-th/9312104

The Verlinde Algebra And The Cohomology Of The Grassmannian

Edward Witten
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Abstract

The article is devoted to a quantum field theory explanation of the relationship (noticed some years ago by Gepner) between the Verlinde algebra of the group $U(k)$ at level $N-k$ and the cohomology of the Grassmannian. The argument proceeds by starting with the two dimensional sigma model whose target space is the Grassmannian and integrating out some fields in a standard way. It has long been known that the resulting low energy effective action describes a theory with a mass gap; the novelty here is that this theory in fact is equivalent at long distances to a gauged WZW model of $U(k)/U(k)$, and hence is related to the Verlinde algebra.

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Edward Witten. 1993-12-13. The Verlinde Algebra And The Cohomology Of The Grassmannian. https://arxiv.org/abs/hep-th/9312104

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