Complex Systems, Nonlinear dynamics, Biomechanics & Biology-motivated problems, Theoretical Soft Condensed Matter & Polymer Physics
Know more: Centre for Complex Systems & Soft Matter Physics
Teaching Experience in the recent past:
Core courses:
- Advanced mathematical physics-1 (including linear algebra and vector spaces & tensor analysis, introduction to stochastic processes, etc) for the Physics Ph.D. programme
- Advanced mathematical physics-2 (including fluid mechanics and other topics) for the Physics Ph.D. programme
- Research & Publication Ethics for the Ph.D. programme
- Physics-1 (classical physics theory: including classical mechanics, E&M, thermodynamics, waves, etc.) for the Integrated M.Tech programme
- Physics-2 (modern physics theory: including statistical mechanics, quantum mechanics, special relativity, nuclear physics, etc.) for the Integrated M.Tech programme
- Physics Laboratory-1 for the Integrated M.Tech programme
- Physics Laboratory-2 for the Integrated M.Tech programme
Elective courses:
- Intoduction to nonlinear dynamical systems
- Elements of statistical physics
- Fundamentals of theoretical neuroscience
Research Guidance:
M. Tech. & M.Sc. Theses supervised:
At IIIT Bangalore:
- Mr. Amogh Johri, "Dynamical behaviour and learning algorithms for theta neuron coupled models & networks", integrated M. Tech. thesis, International Institute of Information Technology Bangalore (2022).
At the University of Hyderabad:
- Mr. G. Naresh Raghava, "Aspects of General Relativity & Astrophysics", M. Sc. Physics project, School of Physics, University of Hyderabad (2012).
- Mr. Tarak K. Patra, "Statistical Physics of Computationally Hard Problems", M.Tech (Computational Techniques) Thesis, School of Physics, University of Hyderabad, (2008).
Courses taught earlier:
At the University of Hyderabad, Hyderabad (April, 2007 - May, 2012):
- Mathematical Physics (IP 452 / PY 204) for 6th Semester Integrated Masters programme, School of Physics, University of Hyderabad.
- December 2010 - April 2011,
- December 2009 - April 2010.
- Classical Mechanics (PY 402) (core course), M.Sc. Physics, University of Hyderabad, July- November 2007 session.
- Designed the syllabus & course material for the core course on Combustion & Related Phenomena (HEMPH 901) for Ph.D. & Research Students at ACRHEM, University of Hyderabad.
- Taught the course for the semesters:
- July - November, 2010,
- July - November, 2008,
- January - May, 2008.
- Delivered some guest lectures as an introduction to polymers and polymer physics as part of a course on Concepts of Materials introduced at the School of Engineering, University of Hyderabad, in September, 2008.
Research interests:
Our research interests focus on the study of complex systems and soft matter physics. This involves the modelling of various physical & biological systems, using dynamical systems theory and methods. These include biomechanics (the dynamics and control of vesicular nanotubulation), diverse complex systems, instabilities in nonlinear systems, the dynamics of macromolecular & micellar solutions and their behaviour in flows, the control of block copolymer morphology using electric fields, bubble dynamics & cavitation and the related phenomenon of single-bubble sonoluminiscence, instabilities in combustion phenomena, and aspects of climate modelling using a dynamical systems approach. Other research interests include certain aspects of quantum computation.
Brief summaries of some of the topics of our research are given below.
Know more: Centre for Complex Systems & Soft Matter Physics, https://www.iiitb.ac.in/cssmp/
Locating phase transitions in computationally hard problems
We discuss how phase-transitions may be detected in computationally hard problems in the context of Anytime Algorithms. Treating the computational time, value and utility functions involved in the search results in analogy with quantities in statistical physics, we indicate how the onset of a computationally hard regime can be detected and the transit to higher quality solutions be quantified by an appropriate response function. The existence of a dynamical critical exponent is shown, enabling one to predict the onset of critical slowing down, in the specific case of a Travelling Salesman Problem. This can be used as a means of improving efficiency and speed in searches, and avoiding needless computation.
Dynamics of vesicular nanotubulation
An interesting problem, one motivated by nanotubulation experiments concerns the dynamics of vesicle-pulling. This phenomenon of nanotube formation has practical applications – e.g., the formation of networks of nanotubes and containers that can be formed through mechanical excitation of vesicles, useful in making nanofluid devices & drug delivery systems. We have theoretically investigated the dynamical behaviour of a vesicle attached to a substrate and pulled with a constant velocity. We have considered the effects of change in vesicular geometry and various dissipative effects that come into play as the lipid layers are pulled out to form a nanotube. Our theoretical model is in substantial qualitative agreement with experimental observations.
Bubble dynamics and cavitation
Another problem under study is that of bubble dynamics and cavitation in fluids. This occurs in various situations and is associated with various phenomena, ranging from the cavitation damage to propellers of ships, single and multi-bubble sonoluminescence, forced bubble oscillations in living tissue, shock-wave generation and cavitation by living organisms such as shrimps, the sound associated with running water -- the list goes on and on. A forced oscillating bubble in a fluid is a very rich nonlinear system which can show very surprising and interesting behaviour. We study the dynamics of such a system, under acoustic forcing, using a modified Rayleigh- Plesset equation, investigating the effect of various physical parameters.
Dynamical instabilities, noise & sensory detection
Living things depend upon their various senses for their survival. Sensory cells detecting different modalities have developed sophisticated mechanisms to convey the various features of the external environment to the living system in the shortest possible time. The essential nonlinearities inherent in the signal transduction mechanism can take advantage of the noise from the environment the system is subject to, to display a highly amplified response to stimuli in a frequency-selective manner. We study the role of the Hopf bifurcation in detection of stimuli in sensory processes.
Synchronization in nonlinear systems
We are also interested in the synchronization behaviour of nonlinear systems. Addition of weak noise may cause synchronization to occur in some systems. We have studied noise-induced synchronization in a system of coupled nonlinear oscillators which exhibit self-sustained oscillations through global bifurcations.
Dynamics of coupled neurons
Studies of neuronal firing behaviour include investigations of neuron models as flows & maps, constructing models that replicate observed bursting behaviour, and understanding the dynamics of neuronal firing from a dynamical systems theory point of view.
Instabilities in combustion
We are also investigating, theoretically, the behaviour of combustion growth fronts under various conditions. Phenomena like fingering instabilities & effect of geometry on the combustion dynamics are sought to be understood. Another aspect being investigated focuses on issues of partial combustion.
Polyelectrolyte solutions, micelles, block copolymers
Other topics include studies of the viscosity of polymer and polyelectrolyte solutions and of micellar systems, the control of the orientational morphology of block copolymers at small length scales by means of electric fields, the effect of flows on rheological and configurational properties of a polymer, etc.
Other work
Other work includes modelling climate phenomena, modelling of ecological systems, etc., and aspects of quantum computing.
