Walls from fluxes: An Analytic RG flow

We construct supergravity solutions describing the near horizon limit of D1D5 systems with non-trivial boundary conditions. Upon reduction to five dimensions they define Melvin universes with NS-NS/RR fluxes, that smoothly interpolate between two different AdS3 geometries which define fixed points for the RG-flow of the dual field theory. We discuss the decoupling limits at the two ends of the flow. We also present a systematic study of the global properties of our solution. In particular we show how, although the AdS3 × S3 global isometry group is broken down to SU(2)R × U(1)3 by global identifications, a full two-dimensional conformal group of isometries, with the expected central charge, is restored at infinity.