标题： 七维流形上M理论中的流与G结构 显示英文标题

标题： Fluxes in M-theory on 7-manifolds and G structures

摘要： 我们考虑了带有4形式通量的M理论在7流形上的扭曲紧化，并研究了超对称所施加的限制条件。只要7流形只支持一个Killing旋量，我们就可以从Killing旋量方程推断出非平凡的4形式通量一定会使外部的4维空间弯曲。另一方面，如果7流形至少有两个Killing旋量，则存在一个非平凡的Killing矢量，这使得7流形可以约化为一个6流形，并且我们证实如果包含非平凡的SU(3)结构，则可以引入4形式通量。 显示英文摘要

摘要： We consider warp compactifications of M-theory on 7-manifolds in the presence of 4-form fluxes and investigate the constraints imposed by supersymmetry. As long as the 7-manifold supports only one Killing spinor we infer from the Killing spinor equations that non-trivial 4-form fluxes will necessarily curve the external 4-dimensional space. On the other hand, if the 7-manifold has at least two Killing spinors, there is a non-trivial Killing vector yielding a reduction of the 7-manifold to a 6-manifold and we confirm that 4-form fluxes can be incorporated if one includes non-trivial SU(3) structures.