Generalized Wigner–Inönü contractions and Maxwell (super)algebras

We consider a class of generalized Wigner–Inönü contractions for the semidirect product of two particularly related semisimple Lie (super)algebras. A special class of such contractions provides the $D=4$ Maxwell algebra and the recently introduced simple $D=4$ Maxwell superalgebra. Further we present two types of $D=4$ $N$-extended Maxwell superalgebras, the nonstandard one for any $N$ with $\frac12N(N-1)$ central charges and the standard one, for even $N=2k$, with $k(2k-1)$ internal symmetry generators.