In\"on\"u-Wigner Contraction and $D=2+1$ Supergravity

We present a generalization of the standard In"on"u-Wigner contraction by rescaling not only the generators of a Lie superalgebra but also the arbitrary constants appearing in the components of the invariant tensor. The procedure presented here allows to obtain explicitly the Chern-Simons supergravity action of a contracted superalgebra. In particular we show that the Poincar'e limit can be performed to a $D=2+1$ $(p,q)$ $$ Chern-Simons supergravity in presence of the exotic form. We also construct a new three-dimensional $(2,0)$ Maxwell Chern-Simons supergravity theory as a particular limit of $(2,0)$ $AdS$ -Lorentz supergravity theory. The generalization for $\mathcal{N}=p+q$ gravitini is also considered.