Extended Supersymmetric BMS${}_3$ algebras and Their Free Field Realisations

Abstract

We study $N=(2,4,8)$ supersymmetric extensions of the three dimensional BMS algebra (BMS${}_3$) with most generic possible central extensions. We find that $N$-extended supersymmetric BMS${}_3$ algebras can be derived by a suitable contraction of two copies of the extended superconformal algebras. Extended algebras from all the consistent contractions are obtained by scaling left-moving and right-moving supersymmetry generators symmetrically, while Virasoro and R-symmetry generators are scaled asymmetrically. On the way, we find that the BMS/GCA correspondence does not in general hold for supersymmetric systems. Using the ${\hat{I}}^2$-${\hat{I}}^3$ and the $\mathfrak{b}$-$\mathfrak{c}$ systems, we construct free field realisations of all the extended super-BMS${}_3$ algebras.

25 pages, 1 table