PT-symmetry breaking hamiltonian interactions in BF models
  The PT-symmetry breaking, consistent hamiltonian interactions in all $n\geq 4$ spacetime dimensions that can be added to an abelian BF model involving a set of scalar fields, two sorts of one-forms, and a system of two-forms are obtained by means of the hamiltonian deformation procedure based on local BRST cohomology. This paper enhances one of our previous works, where only PT-invariant deformations were considered. The associated coupled theory is an interacting, topological BF model exhibiting an open gauge algebra and on-shell reducibility relations. 
E. M. Cioroianu, S. C. Sararu