Extreme near-horizon geometries in D = 11 supergravity preserving four supersymmetries are classified. It is shown that the Killing spinors fall into three possible orbits, corresponding to pairs of spinors defined on the spatial cross-sections of the horizon which have isotropy groups SU(3), G₂, or SU(4). In each case, the conditions on the geometry and the 4-form flux are determined. The integrability conditions obtained from the Killing spinor equations are also investigated.

A preprint version of the article is available at ArXiv.

中文翻译：

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N = 4 D = 11 超重力中的近地平线几何

D = 11 超重力保持四个超对称的极端近地平线几何被分类。结果表明，Killing 旋量分为三个可能的轨道，对应于定义在视界空间截面上的旋量对，它们具有各向同性群 SU(3)、G ₂或 SU(4)。在每种情况下，确定几何条件和 4 型通量。还研究了从 Killing 旋量方程获得的可积性条件。

该文章的预印版可在 ArXiv 上获得。