Publications

@article{Singha2022,
title = {Phase-locking in k-partite networks of delay-coupled oscillators},
author = {J Singha and R Ramaswamy},
url = {https://www.sciencedirect.com/science/article/pii/S0960077922001576},
doi = {https://doi.org/10.1016/j.chaos.2022.111947},
issn = {0960-0779},
year = {2022},
date = {2022-03-11},
journal = {Chaos, Solitons, and Fractals},
volume = {157},
pages = {111947},
abstract = {We examine the dynamics of an ensemble of phase oscillators that are divided in k sets, with time-delayed coupling interactions only between oscillators in different sets or partitions. The network of interactions thus forms a k−partite graph. A variety of phase-locked states are observed; these include, in addition to the fully synchronized in-phase solution, splay cluster solutions in which all oscillators within a partition are synchronised and the phase differences between oscillators in different partitions are integer multiples of 2π/k. Such solutions exist independent of the delay and we determine the generalised stability criteria for the existence of these phase-locked solutions. With increase in time-delay, there is an increase in multistability, the generic solutions coexisting with a number of other partially synchronized solutions. The Ott-Antonsen ansatz is applied for the special case of a symmetric k−partite graph to obtain a single time-delayed differential equation for the attracting synchronization manifold. Agreement with numerical results for the specific case of oscillators on a tripartite lattice (the k=3 case) is excellent.},
keywords = {Delay coupling, Network},
pubstate = {published},
tppubtype = {article}
}

@article{Saxena2012,
title = {Amplitude death: The emergence of stationarity in coupled nonlinear systems},
author = {Garima Saxena and Awadhesh Prasad and Ram Ramaswamy},
url = {https://ramramaswamy.org/papers/RC43.pdf},
doi = {10.1016/j.physrep.2012.09.003},
issn = {03701573},
year = {2012},
date = {2012-01-01},
journal = {Physics Reports},
volume = {521},
number = {5},
pages = {205–228},
abstract = {When nonlinear dynamical systems are coupled, depending on the intrinsic dynamics and the manner in which the coupling is organized, a host of novel phenomena can arise. In this context, an important emergent phenomenon is the complete suppression of oscillations, formally termed amplitude death (AD). Oscillations of the entire system cease as a consequence of the interaction, leading to stationary behavior. The fixed points which the coupling stabilizes can be the otherwise unstable fixed points of the uncoupled system or can correspond to novel stationary points. Such behavior is of relevance in areas ranging from laser physics to the dynamics of biological systems. In this review we discuss the characteristics of the different coupling strategies and scenarios that lead to AD in a variety of different situations, and draw attention to several open issues and challenging problems for further study. textcopyright 2012 Elsevier B.V.},
keywords = {Amplitude quenching, Bifurcation, Control, Fixed-point solution, Interaction, Network, Synchronization},
pubstate = {published},
tppubtype = {article}
}