Effect of phase-lag on synchronization in adaptive multilayer networks with higher-order interactions

We investigate the transition to synchronization in adaptive multilayer networks with higher-order interactions, both analytically and numerically, in the presence of phase frustration (β). The higher-order topology consists of pairwise and triadic couplings. The analytical framework for the investigation is based on the Ott-Antonsen ansatz, which leads to a convenient low-dimensional model. Extensive bifurcation analysis of the low-dimensional model and the numerical simulation of the full networks are performed to explore the paths to synchronization. The combined analysis shows a complex dependence of the transition to synchronization on adaptation exponents, coupling strengths, phase-lag parameter, and multilayer configuration. Various types of transitions to synchronization, namely continuous, tiered, and explosive, are exhibited by the system in different regions of the parameter space. In all the cases, a satisfactory match between the low-dimensional model and the numerical simulation results is observed. The origin of different transitions to synchronization is clearly understood using the low-dimensional model. Exploration of a wide region of the parameter space suggests that the phase frustration parameter inhibits tiered as well as explosive synchronization transitions for fixed triadic coupling strength (K_{2}). On the other hand, discontinuous transition is promoted by the phase frustration parameter for fixed pairwise coupling strength (K_{1}). Moreover, the exponent of the adaptation function with the pairwise coupling decreases the width of the hysteresis, despite the dominance of the higher-order coupling for fixed β and K_{2}. While the exponent of the function adapted with higher-order coupling shows the opposite effect, it promotes bistability in spite of dominance of pairwise coupling strength for fixed β and K_{1}.