Publications

@article{Agrawal2010,
title = { Quasiperiodic forcing of coupled chaotic systems},
author = {M Agrawal, A Prasad, and R Ramaswamy},
url = {https://link.aps.org/doi/10.1103/PhysRevE.81.026202},
doi = {10.1103/PhysRevE.81.026202},
year = {2010},
date = {2010-02-04},
journal = {Physical Review E},
volume = {81},
number = {2},
pages = {026202},
abstract = {We study the manner in which the effect of quasiperiodic modulation is transmitted in a coupled nonlinear dynamical system. A system of Rössler oscillators is considered, one of which is subject to driving, and the dynamics of other oscillators which are, in effect, indirectly forced is observed. Strange nonchaotic dynamics is known to arise only in quasiperiodically driven systems, and thus the transmitted effect is apparent when such motion is seen in subsystems that are not directly modulated. We also find instances of imperfect phase synchronization with forcing, where the system transits from one phase synchronized state to another, with arbitrary phase slips. The stability of phase synchrony for arbitrary initial conditions with identical forcing is observed as a general property of strange nonchaotic motion.},
keywords = {Quasiperiodicity, Strange nonchaotic attractors, Synchronization},
pubstate = {published},
tppubtype = {article}
}

@article{Datta2005,
title = {Critical localization and strange nonchaotic dynamics: The Fibonacci chain},
author = {S Datta, S S Negi, R Ramaswamy, and U Feudel
},
url = {https://doi.org/10.48550/arXiv.nlin/0104054},
doi = {10.48550/arXiv.nlin/0104054},
year = {2005},
date = {2005-01-01},
journal = {International Journal of Bifurcation and Chaos},
volume = {15},
number = {4},
pages = {1493-1501},
abstract = {The discrete Schrödinger equation with a quasiperiodic dichotomous potential specified by the Fibonacci sequence is known to have a singular continuous eigenvalue spectrum with all states being critically localized. This equation can be transformed into a quasiperiodic skew product dynamical system. In this iterative mapping which is entirely equivalent to the Schrödinger problem, critically localized states correspond to fractal attractors which have all Lyapunov exponents equal to zero. This provides an alternate means of studying the spectrum, as has been done earlier for the Harper equation. We study the spectrum of the Fibonacci system and describe the scaling of gap widths with potential strength.},
keywords = {Strange nonchaotic attractors},
pubstate = {published},
tppubtype = {article}
}

@article{Negi2000,
title = {Bifurcations and transitions in the quasiperiodically driven logistic map},
author = {Surendra Singh Negi and Awadhesh Prasad and Ramakrishna Ramaswamy},
url = {https://ramramaswamy.org/papers/078.pdf},
doi = {10.1016/S0167-2789(00)00110-X},
issn = {01672789},
year = {2000},
date = {2000-01-01},
journal = {Physica D: Nonlinear Phenomena},
volume = {145},
number = {1-2},
pages = {1–12},
abstract = {We discuss several bifurcation phenomena that occur in the quasiperiodically driven logistic map. This system can have strange nonchaotic attractors (SNAs) in addition to chaotic and regular attractors; on SNAs the dynamics is aperiodic, but the largest Lyapunov exponent is nonpositive. There are a number of different transitions that occur here, from periodic attractors to SNAs, from SNAs to chaotic attractors, etc. We describe some of these transitions by examining the behavior of the largest Lyapunov exponent, distributions of finite time Lyapunov exponents and the invariant densities in the phase space. textcopyright 2000 Elsevier Science B.V.},
keywords = {Lyapunov exponent, Quasiperiodically driven logistic map, Strange nonchaotic attractors},
pubstate = {published},
tppubtype = {article}
}