Prof G. Ambika and her group focus on understanding complex systems from the theory of nonlinear dynamics and complex networks and measures of their complexity from observational data.
Life Of A Researcher | Ep 1: in talks with Prof. G Ambika
- Sandip V. George, Sneha Kachhara and G. Ambika , Early warning signals for critical transitions in complex systems, 2023, Phys. Scr. 98 072002 https://doi.org/10.1088/1402-4896/acde20
- Vedang Tamhane and G. Ambika , Structure and Stability of the Indian Power Transmission Network, 2023 J. Phys. Complex. 4, 025014. https://doi.org/10.1088/2632-072X/acd611
Dynamics of complex systems
- Frequency chimera - introduced a new chimera state , in coupled systems with multiple dynamical time scales
- Chimera states in multiplex networks: occurrence of Chimera states in one layer due to the influence of another layer in multiplex recurrence networks.
- Synapse loss and progress of Alzheimer's disease: a network model of neurons, that explains the loss of coordinated activity and transmission efficiency among neurons that manifests over time due to loss functional synapses.
- A novel coupling scheme for delay or anticipatory synchronization: with variable delay with applications in secure communication
- Environmental coupling in complex systems: emergent states like amplitude death and control of spatio temporal dynamics
- RAndom Interacting Network (RAIN) model: novel scheme to study the interactions between complex networks
- Evolving bimodal networks: A new procedure for constructing a network with bimodal degree distribution using immunity score
- Degree preserving rewiring methods and effects of link deletion: effects on clustering and degree-correlations in directed networks.
Dynamics from data of Complex systems
- Multiplex Recurrence networks from multichannel ECG data: an integrated approach to analyze the multi-lead ECG data is possible using multiplex recurrence networks (MRNs) constructed from the embedded dynamics from channel wise data. This helps to differentiate various disease cases from healthy ones.
- Early warning signals for the mysterious dimming of the star Betelgeuse: proposed signals of a critical transition in its pulsation dynamics, as indicated by increase in values of a set of measures, responsible for the dimming episode of 2019-20
- Classification of close binary stars using recurrence networks: use of machine learning algorithms applied to measures of recurrence networks and nonlinear time series analysis to differentiate between classes of close binary stars.
- Bimodal degree distribution and scaling in Recurrence networks from ECG data
- Complexity and connectivity measures: Multifractal measures computed from physiological and astrophysical data
- New measures: introduced measures like heterogeneity measure, entropy and weighted recurrence networks for studying recurrence patterns in data
- Natural numbers network using the divisibility pattern of natural numbers for growing a complex network and its complexity measures for prime and composite numbers
- Community structured modular network of chaotic neurons with inhibitory synapses
- Heterogeneity in the dynamical time scales of connected nonlinear dynamical systems
- Model for primary and secondary dengue infections
- Virus Immune Drug dynamics
- Stochastic Resonance & Vibrational resonance, lattice stochastic resonance
- Universal indices and RG analysis in 1-d maps
- Hamiltonian format for quadratically damped nonlinear systems