BMS field theory and holography in asymptotically flat space-times
Claudio Dappiaggi
TL;DR
This work advances a holographic perspective for asymptotically flat spacetimes by constructing a free BMS field theory on future/past null infinity and analyzing its quantum structure. It develops the BMS-Klein-Gordon framework, derives a boundary path integral with constraints, and obtains a boundary two-point function governed by a differential equation that encodes evolution along pure supertranslations. A null surface formulation is proposed to connect boundary data with bulk geometry, suggesting that cut functions Z(x^a,z,ar z) can, at least in Minkowski space, reproduce the bulk propagator and potentially enable bulk reconstruction in more general backgrounds. The study highlights the nontrivial IR structure associated with BMS supertranslations and points toward a holographic program for flat spacetimes, including future work on interactions and curved geometries.
Abstract
We explore the holographic principle in the context of asymptotically flat space-times by means of the asymptotic symmetry group of this class of space-times, the so called Bondi-Metzner-Sachs (BMS) group. In particular we construct a (free) field theory living at future (or past) null infinity invariant under the action of the BMS group. Eventually we analyse the quantum aspects of this theory and we explore how to relate the correlation functions in the boundary and in the bulk.
