On Étale Algebras and Bosonic Fusion 2-Categories

Abstract: We classify all connected and Lagrangian \'etale algebras in the Drinfeld center $\mathscr{Z}_1(\mathbf{2Vect}^\pi_G)$, where $G$ is a finite group and $\pi$ is a 4-cocycle on $G$. By D\'ecoppet's result every bosonic fusion 2-category $\mathfrak{C}$ has its Drinfeld center equivalent to $\mathscr{Z}_1(\mathbf{2Vect}^\pi_G)$ for some $G$ and $\pi$. Combining this fact with classification of Lagrangian algebras in $\mathscr{Z}_1(\mathbf{2Vect}^\pi_G)$, we obtain a classification of bosonic fusion 2-categories.