Categorical Hopf map

Abstract: We introduce the categorical Hopf map as a categorical principal bundle over the two-dimensional sphere with fibre the categorical circle of Nora Ganter. We investigate its connection to the Hopf map. We present a factorisation of the categorical Hopf map through the Hopf map and the basic bundle gerbe over the three-dimensional sphere. We discuss three equivalent constructions for the basic bundle gerbe over the three-dimensional sphere. Finally, we conjecture that the categorical group String(3) is equivalent to the categorical group of symmetries of the categorical Hopf map.