Higher-Dimensional Supertranslations and Weinberg’s Soft Graviton Theorem
نویسندگان
چکیده
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.
منابع مشابه
BMS supertranslations and Weinberg’s soft graviton theorem
Recently it was conjectured that a certain infinite-dimensional “diagonal” subgroup of BMS supertranslations acting on past and future null infinity (I − and I +) is an exact symmetry of the quantum gravity S-matrix, and an associated Ward identity was derived. In this paper we show that this supertranslation Ward identity is precisely equivalent to Weinberg’s soft graviton theorem. Along the w...
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