Maximally extended sl(2|2), q-deformed d(2,1;epsilon) and 3D kappa-Poincar\'e

Understand

We show that the maximal extension sl(2) times psl(2|2) times C3 of the sl(2|2) superalgebra can be obtained as a contraction limit of the semi-simple superalgebra d(2,1;epsilon) times sl(2).

• We reproduce earlier results on the corresponding q-deformed Hopf algebra and its universal R-matrix by means of contraction.
• We make the curious observation that the above algebra is related to kappa-Poincar\'e symmetry.
• When dropping the graded part psl(2|2) we find a novel one-parameter deformation of the 3D kappa-Poincar\'e algebra.