  Supertranslation Goldstone lies in certain "exceptional series"
representations of $SL(2,\mathbb{C})$. Interestingly, $m^2=-3$ scalar tachyon
in three dimensional de Sitter space also lies in the same representation. In
this note, we analyze these theories, focusing on representation-theoretical
aspects, and emphasize that "modulo certain polynomials", there is a unitary
representation of the corresponding symmetry group.
