Orbifolds by 2-groups and decomposition

A bstract In this paper we study three-dimensional orbifolds by 2-groups with a trivially-acting one-form symmetry group BK . These have global two-form symmetry, and so one expects that they decompose into (are equivalent to) disjoint union of other theories, which demonstrate. theories can be interpreted as sigma models on 2-gerbes, whose formal structures reflect properties the orbifold construction.