Minimal W-algebras of ${\mathfrak{so}}_N$ at level minus one

Abstract

For $N\in {\mathbb{Z}}_{\ge 7}$ we show that the simple minimal $\mathcal{W}$-algebra of ${\mathfrak{so}}_N$ at level minus one is isomorphic to the even subalgebra of the tensor product of the simple affine vertex superalgebra of ${\mathfrak{osp}}_{1|2}$ at level $\frac{N-6}{2}$ with $N-4$ free fermions. In particular when $N$ is even this minimal $\mathcal{W}$-algebra is strongly rational as conjectured by Arakawa-Moreau.

13 pages