On the quantum Horn problem

Nicolas Ressayre

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arXiv · 1310.7331

On the quantum Horn problem

Nicolas Ressayre

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Abstract

Let $K$ be a compact, connected, simply-connected simple Lie group. Given two conjugacy classes $\Orb_1$ and $\Orb_2$ in $K$, we consider the multiplicative Horn question: What conjugacy classes are contained in $\Orb_1\cdot\Orb_2$? It is known that answering this question remains to describe a convex polytope $\poly_K$. In 2003, Teleman-Woodward gave a complete list of inequalities for $\poly_K$. Their list contains redundant inequalities. In this paper, we describe $\poly_K$ by a smaller list of inequalities.

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Nicolas Ressayre. 2013-10-28. On the quantum Horn problem. https://arxiv.org/abs/1310.7331

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