Consistent truncations and generalised geometry Seminar

We show how generalised geometry gives a unified description of consistent truncations of supergravity. In particular we see that all round-sphere S^d geometries admit so-called "generalised parallelisations", giving a simple way to understand the remarkable consistent truncations on S^7, S^5 and S^4.

Abstract:
The study of consistent truncations of gravitational theories is an old subject going back to work of Jordan and Pauli. It is well known that reductions on group manifolds are consistent, but there is also a mysterious set of truncations on very particular coset manifolds with non-trivial form-field fluxes. We show how generalised geometry gives a unified description of such reductions. In particular we demonstrate that all round-sphere S^d geometries admit "generalised parallelisations”, giving a simple way to understand the remarkable consistent truncations on S7, S5 and S4.