Generalised U-dual solutions via ISO(7) gauged supergravity

Abstract: We study a solution generating technique in supergravity which can be viewed as a generalised version of U-duality, taking solutions of type IIA supergravity on a 6-sphere with RR flux to new solutions of 11-dimensional supergravity. The new solutions are characterised by an underlying 6-algebra structure. Our construction provides an 11-dimensional uplift of four-dimensional ISO(7) gauged supergravity, using $E_7$ exceptional geometry techniques. We focus on an example where we start with the D2 solution in type IIA supergravity and construct a new $\tfrac12$-BPS 11-dimensional solution.