Bubbling 1/2 BPS solutions of minimal six-dimensional supergravity
  We continue our previous analysis (hep-th/0412045) of 1/2 BPS solutions to minimal 6d supergravity of bubbling form. We show that, by turning on an axion field in the T^2 torus reduction, the constraint F \wedge F, present in the case of an S^1 x S^1 reduction, is relaxed. We prove that the four-dimensional reduction to a bosonic field theory, whose content is the metric, a gauge field, two scalars and a pseudo-scalar (the axion), is consistent. Moreover, these reductions when lifted to the six-dimensional minimal supergravity represent the sought-after family of 1/2 BPS bubbling solutions. 
James T. Liu and Diana Vaman