Effect of repulsive links on frustration in attractively coupled networks

Abstract: We investigate the impact of attractive-repulsive interaction in networks of limit-cycle oscillators. Mainly we focus on the design principle for generating an anti-phase state between adjacent nodes in a complex network. We establish that a partial negative control throughout the branches of a spanning tree inside the positively coupled limit-cycle oscillators works efficiently well in comparison with randomly chosen negative links to establish zero frustration (anti-phase synchronization) in bipartite graphs. Based on the emergence of zero frustration, we develop a universal 0-$\pi$ rule to understand the anti-phase synchronization in a bipartite graph. Further, this rule is used to construct a non-bipartite graph for a given non-zero frustrated value. We finally show the generality of 0-$\pi$ rule by implementing it in arbitrary undirected non-bipartite graphs of attractive-repulsively coupled limit-cycle oscillators and successfully calculate the non-zero frustration value which matches with numerical data. The validation of the rule is checked through the bifurcation analysis of small networks. Our work may unveil the underlying mechanism of several synchronization phenomena that exist in a network of oscillators having a mixed type of coupling.