BPS bounds in supersymmetric extensions of K field theories
  We demonstrate that in the supersymmetric extensions of a class of generalized (or K) field theories introduced recently, the static energy satisfies a BPS bound in each topological sector. Further, the corresponding soliton solutions saturate the bound. We also find strong indications that the BPS bound shows up in the SUSY algebra as a central extension, as is the case in the well-known supersymmetric field theories with standard kinetic terms. 
C. Adam, J.M. Queiruga, J. Sanchez-Guillen, A. Wereszczynski
hep-th math-ph math.MP