  In this paper we outline the application of decomposition to condensation
defects and their fusion rules. Briefly, a condensation defect is obtained by
gauging a higher-form symmetry along a submanifold, and so there is a natural
interplay with notions of decomposition, the statement that d-dimensional
quantum field theories with global (d-1)-form symmetries are equivalent to
disjoint unions of other quantum field theories. We will also construct new
(sometimes non-invertible) defects, and compute their fusion products, again
utilizing decomposition. An important role will be played in all these analyses
by theta angles for gauged higher-form symmetries, which can be used to select
individual universes in a decomposition.
