标题： 更高次的su(N)张量积 显示英文标题

标题： Higher su(N) tensor products

摘要： 我们将最近关于普通su(N)张量积重数的结果推广到高阶su(N)张量积。 特别强调的是四点耦合，其中考虑了四个最高权模的张量积。 在分解中单态出现的次数即为相应的重数。 在这个框架下，普通的张量积对应于三点耦合。 如同在那种情况下一样，四点重数可以明确地表示为一个多重求和，用于测量凸多胞体的离散体积。 这种描述也可以扩展到更高点耦合。 我们还讨论了确定较高点耦合是否存在（即相应的重数是否非零）的问题。 解决方案是一组在Dynkin标记中的不等式。 显示英文摘要

摘要： We extend our recent results on ordinary su(N) tensor product multiplicities to higher su(N) tensor products. Particular emphasis is put on four-point couplings where the tensor product of four highest weight modules is considered. The number of times the singlet occurs in the decomposition is the associated multiplicity. In this framework, ordinary tensor products correspond to three-point couplings. As in that case, the four-point multiplicity may be expressed explicitly as a multiple sum measuring the discretised volume of a convex polytope. This description extends to higher-point couplings as well. We also address the problem of determining when a higher-point coupling exists, i.e., when the associated multiplicity is non-vanishing. The solution is a set of inequalities in the Dynkin labels.