BMS charge algebra

Glenn Barnich, Cédric Troessaert
2011 Journal of High Energy Physics  
The surface charges associated with the symmetries of asymptotically flat four dimensional spacetimes at null infinity are constructed. They realize the symmetry algebra in general only up to a field-dependent central extension that satisfies a suitably generalized cocycle condition. This extension vanishes when using the globally well defined BMS algebra. For the Kerr black hole and the enlarged BMS algebra with both supertranslations and superrotations, some of the supertranslations charges
more » ... verge whereas there are no divergences for the superrotation charges. The central extension is proportional to the rotation parameter and involves divergent integrals on the sphere.
doi:10.1007/jhep12(2011)105 fatcat:4v2wbquehvhotaxaud54sxav3y