Multipartite nonlocality swapping

Abstract: Nonlocality swapping of bipartite binary correlated boxes can be realized by a \emph{coupler} ($\chi$) in nonsignaling models. By studying the swapping process we find that the previous bipartite coupler can be applied to the swapping of two multipartite boxes, and then generate a multipartite box with more users than that of any of the boxes before swapping. Here quantum bound still appears in the scheme. The bipartite coupler also can be applied to a hybrid scheme of generating a multipartite extremal box from many PR boxes. As the analogue of multipartite entanglement swapping, we generalize the nonlocality swapping of bipartite binary boxes to multipartite binary boxes by using a multipartite coupler $\chi_{N}$, and get the probability of success by connecting the coupler to the generalized Svetlichny inequality. The multipartite coupler acting on many multipartite boxes makes multipartite nonlocality swapping be a more efficient device to manipulate nonlocality between many users. The results show that Tsirelson's bound for quantum nonlocality emerges only when two of the $n$ boxes involved in the coupler process are noisy ones.