The Peter-Weyl Theorem for SU(1|1)

We study a generalization of the results \in \cite{cfk} to the case of $SU(1\mathrm{\mid }1)$ interpreted as the supercircle $S^{1\mathrm{\mid }2}$. We describe all of its finite dimensional complex irreducible representations, we give a reducibility result for representations not containing the trivial character, and we compute explicitly the corresponding matrix elements. In the end we give the Peter-Weyl theorem for $S^{1\mathrm{\mid }2}$.