Twisted Sectors for Tensor Product Vertex Operator Algebras Associated to Permutation Groups

Abstract: Let V be a vertex operator algebra, and for k a positive integer, let g be a k-cycle permutation of the vertex operator algebra V⊗k. We prove that the categories of weak, weak admissible and ordinary g-twisted modules for the tensor product vertex operator algebra V⊗k are isomorphic to the categories of weak, weak admissible and ordinary V-modules, respectively. The main result is an explicit construction of the weak g-twisted V⊗k-modules from weak V-modules. For an arbitrary permutation automorphism g of V⊗k the category of weak admissible g-twisted modules for V⊗k is semisimple and the simple objects are determined if V is rational. In addition, we extend these results to the more general setting of γg-twisted V⊗k-modules for γ a general automorphism of V acting diagonally on V⊗k and g a permutation automorphism of V⊗k.