Inverse Reduction for Hook-Type W-Algebras

Originating in the work of A.M. Semikhatov and D. Adamović, inverse reductions are embeddings involving W-algebras corresponding to the same Lie algebra but different nilpotent orbits. Here, we show that an inverse reduction embedding between the affine slₙ₊₁ sl n + 1 vertex operator algebra and the minimal slₙ₊₁ sl n + 1 W-algebra exists. This generalises the realisations for $$n=1,2$$ n = 1 , 2 in Adamović (Commun Math Phys 366:1025–1067, 2019), Adamović (Math Ann 1–44, 2023). A similar argument is then used to show that inverse reduction embeddings exists between all hook-type slₙ₊₁ sl n + 1 W-algebras, which includes the principal/regular, subregular, minimal slₙ₊₁ sl n + 1 W-algebras, and the affine slₙ₊₁ sl n + 1 vertex operator algebra. This generalises the regular-to-subregular inverse reduction of Fehily (Commun Contemp Math 2250049, 2022), and similarly uses free-field realisations and their associated screening operators.