Higher-Dimensional Supertranslations and Weinberg's Soft Graviton Theorem
Abstract
Asymptotic symmetries of theories with gravity in d=2m+2 spacetime dimensions are reconsidered for m>1 in light of recent results concerning d=4 BMS symmetries. Weinberg's soft graviton theorem in 2m+2 dimensions is re-expressed as a Ward identity for the gravitational S-matrix. The corresponding asymptotic symmetries are identified with 2m+2-dimensional supertranslations. An alternate derivation of these asymptotic symmetries as diffeomorphisms which preserve finite-energy boundary conditions at null infinity and act non-trivially on physical data is given. Our results differ from those of previous analyses whose stronger boundary conditions precluded supertranslations for d>4. We find for all even d that supertranslation symmetry is spontaneously broken in the conventional vacuum and identify soft gravitons as the corresponding Goldstone bosons.
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Cite
@article{arxiv.1502.07644,
title = {Higher-Dimensional Supertranslations and Weinberg's Soft Graviton Theorem},
author = {Daniel Kapec and Vyacheslav Lysov and Sabrina Pasterski and Andrew Strominger},
journal= {arXiv preprint arXiv:1502.07644},
year = {2017}
}
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24 pages