Decomposition in 2d non-invertible gaugings

Abstract: We extend decomposition to 2d QFT's with a gauged $\text{Rep}(H)$ symmetry category for $H$ a finite-dimensional semisimple Hopf algebra with $\text{Rep}(G)$ trivially-acting and $\text{Vec}(\Gamma)$ the remaining symmetry, for $G,\Gamma$ finite groups. We check our extension by explicitly computing partition functions, and by verifying that previous results arise as special cases. Then, drawing from these computations, we formulate a plausible decomposition conjecture for the even more general case of $\text{Rep}(H'')$ trivially-acting and $\text{Rep}(H')$ the remaining symmetry, for $H',H''$ Hopf algebras, not necessarily associated with groups.