The maximal quantum group-twisted tensor product of C*-algebras

Abstract: We construct a maximal counterpart to the minimal quantum group-twisted tensor product of $C^{*}$-algebras studied by Meyer, Roy and Woronowicz, which is universal with respect to representations satisfying braided commutation relations. Much like the minimal one, this product yields a monoidal structure on the coactions of a quasi-triangular $C^{*}$-quantum group, the horizontal composition in a bicategory of Yetter-Drinfeld $C^{*}$-algebras, and coincides with a Rieffel deformation of the non-twisted tensor product in the case of group coactions.