标题： 关于M理论和弦理论中增强规范对称性的注记 显示英文标题

标题： A Note on Enhanced Gauge Symmetries in M- and String Theory

摘要： 存在两种不同的机制在非微扰弦/M理论中实现增强的SU(N)（SO(2N)）规范对称性。 它可以在IIA弦理论或M理论中出现在A_{N-1} (D_N)类型奇点附近，其中环绕两个圈的膜变得无质量，或者由于重合的D膜（以及定向平面）导致在D膜之间延伸的开弦变得无质量。 在本文中，我们通过展示M理论中的一个配置来揭示这两种机制之间的关系，该配置在一种极限下可以视为环绕两个圈的膜具有A_{N-1} (D_N)类型的交矩阵，在另一种极限下可以视为在$N$ Dirichlet 6膜之间延伸的开弦（在存在定向平面的情况下）。 显示英文摘要

摘要： Two different mechanisms exist in non-perturbative String / M- theory for enhanced SU(N) (SO(2N)) gauge symmetries. It can appear in type IIA string theory or M-theory near an A_{N-1} (D_N) type singularity where membrnes wrapped around two cycles become massless, or it can appear due to coincident D-branes (and orientifold planes) where open strings stretched between D-branes become massless. In this paper we exhibit the relationship between these two mechanisms by displaying a configuration in M-theory, which, in one limit, can be regarded as membranes wrapped around two cycles with A_{N-1} (D_N) type intersection matrix, and in another limit, can be regarded as open strings stretched between $N$ Dirichlet 6-branes (in the presence of an orientifold plane).