2011/02/28 by Glenn Barnich, Pierre-Henry Lambert · 1 citation
Physics and Astronomy · #gr-qc #hep-th
paper · pdf · doi:10.1155/2012/197385
published as Advances in Mathematical Physics, vol. 2012, Article ID 197385, 2012 · v2: 16 pages Latex file, considerably expanded version containing transformations of fields and surface charge algebra; v3: cosmetic changes, agrees with published version
arxiv created 2013/01/23 · arxiv updated 2013/01/24
The symmetry algebra of asymptotically flat spacetimes at null infinity in four dimensions in the sense of Newman and Unti is revisited. As in the Bondi-Metzner-Sachs gauge, it is shown to be isomorphic to the direct sum of the abelian algebra of infinitesimal conformal rescalings with bms4. The latter algebra is the semi-direct sum of infinitesimal supertranslations with the conformal Killing vectors of the Riemann sphere. Infinitesimal local conformal transformations can then consistently be included. We work out the local conformal properties of the relevant Newman-Penrose coefficients, construct the surface charges and derive their algebra.