This is a review of selected topics from recent work on symmetry charges in asymptotically flat spacetime done by the author in collaboration with U. Kol and R. Javadinezhad. First we reinterpret the reality constraint on the boundary graviton as the gauge fixing of a new local symmetry, called dual supertranslations. This symmetry extends the BMS group and bears many similarities to the dual (magnetic) gauge symmetry of electrodynamics. We use this new gauge symmetry to propose a new description of the TAUB-NUT space that does not contain closed time-like curves. Next we summarize progress towards the definition of Lorentz and super-Lorentz charges that commute with supertranslations and with the soft graviton mode.

中文翻译：

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扩展 BMS 代数中的费用：定义和应用

这是作者与 U. Kol 和 R. Javadinezhad 合作完成的关于渐近平坦时空中对称电荷的近期工作的选定主题的回顾。首先，我们将边界引力子上的现实约束重新解释为新局部对称性的规范固定，称为双重超平移。这种对称性扩展了 BMS 组，并与电动力学的双（磁）规范对称性有许多相似之处。我们使用这种新的规范对称性提出了对不包含闭合类时曲线的 TAUB-NUT 空间的新描述。接下来，我们总结了洛伦兹和超洛伦兹电荷定义的进展，这些电荷与超平移和软引力子模式相通。