**#TPDP (The Path Dependent Paths, October 02, 2016):**

Are you using a QWERTY keyboard? Why do all clocks go clockwise? Can some systems get locked into sub-optimal states? Why are some processes path dependent and some not? Does the number of variables or the ‘direction’ of change matter? Can future be memory-less, & depend only on the present and not on the past? Can one ‘ensure’ that systems escape unstable equilibria? What role do initial conditions and noise play in arriving at one of multiple possible equilibria? When do systems have unique point convergence or an invariant probability distribution curve? Given enough time, do all systems visit all possible states; why or why not? ‘Why’ does time influence outcomes? Are large complex systems invariably irreversible? How do single/multiple agent/objective systems differ from each other? When does learning take place? Do biological evolutionary ‘equations’ have identifiable optimization function(s) and/or equilibria? Can complex systems be directed to specific (or one of a few) end states? Is persistent socioeconomic inequality also a state of equilibrium, & why might (not) affirmative action work in this context? Is stable equilibrium ‘better’ equilibrium? SynTalk thinks about these & more questions using concepts from game theory & mathematics (Prof. Vivek S. Borkar, IIT Bombay, Mumbai), and statistical mechanics & soft matter physics (Prof. Srikanth Sastry, JNCASR, Bangalore).

Listen in….

SynTalk is pleased and privileged to have hosted the following SynTalkrs (*in alphabetical order*) on its #TPDP show.

**Prof. Vivek Shripad Borkar** (computer science, mathematics) is Institute Chair Professor at the Department of Electrical Engineering, IIT Bombay, Mumbai. He works at the interface of probability and random processes on one hand and optimization and control on the other. He completed his B. Tech. in Electrical Engineering from IIT Bombay (1976), M.S. in Systems and Control Engineering from Case Western Reserve University (1977), USA, and Ph.D. from University of California, Berkeley, USA (1980). He is interested in basic theoretical issues as well as modelling and algorithmic questions and has also done some collaborative work on specific applications to communications and operations research. His research areas are stochastic optimization, probabilistic modelling, probabilistic algorithms, and random processes. Some of his key research themes are adaptation, learning and dynamic models thereof, the phenomenon of metastability and its algorithmic implications, effect of multiple time scales in random dynamics, small noise asymptotics, etc., and also their implications for sciences, engineering and social sciences. He spent 10 years (1989 1999) at IISc, Bangalore, before joining TIFR, Mumbai as a Professor (2000-2011). His key contributions are developing a novel scheme for accelerating simulation based estimation of Markov Chain averages by a conditional version of importance sampling, and a novel scheme called split sampling to accelerate learning algorithms. Prof. Borkar has been awarded Shanti Swarup Bhatnagar Prize (1992), the Distinguished Alumnus Award of IIT Bombay (2000), the Homi Bhabha and JC Bose Fellowships, and the Prasanta Chandra Mahalanobis Medal INSA (2008), among others. He is also an elected Fellow of the Indian National Science Academy (INSA), Indian Academy of Sciences (IAS), Indian National Academy of Engineers (INAE), and Institute of Electrical and Electronic Engineers (IEEE). He has also served on the editorial boards of several academic journals.

**Prof. Srikanth Sastry** (statistical mechanics, soft matter physics) is a Professor at the Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore. He obtained a Bachelor’s degree from Bangalore University (1984), a Master’s degree from IIT Bombay (1986), and a Ph.D. in Physics from Boston University (1993). He has also held postdoctoral positions at National Institutes of Health (USA) & Princeton University. Prof. Sastry’s research interests have been in the area of statistical mechanics, with a focus on aspects of phase transformations and dynamics of liquids and other soft condensed matter, such as transformations that involve unusual phase transitions, metastable states and how they transform to equilibrium states. He studies systems exhibiting slow or glassy relaxation towards equilibrium, how such systems may fail to reach equilibrium and get stuck in non-equilibrium states as a consequence of the complex energy landscapes that they manifest, and the behavior of glassy systems under external driving. Some specific themes in his research have been the anomalous behavior of super-cooled water (a novel transition between two forms of liquid water) and also silicon, slow dynamics and routes to structural arrest or emergence of rigidity (glass transition, gelation, jamming etc.) in super-cooled liquids and other soft matter systems (colloids, gels, granular material), nucleation in metastable liquids, and mechanical behavior and memory effects in driven amorphous solids. Prof. Sastry has been awarded the Shanti Swarup Bhatnagar Prize in physical sciences (2008), JC Bose Fellowship, and the distinguished alumnus award of IIT Bombay (2015). He is also an elected Fellow of the Indian National Science Academy (INSA), Indian Academy of Sciences (IAS), and National Academy of Sciences, India (NASI).

*Note: Any & all errors in the brief profiles above are SynTalk’s own.*

*#TPDP mentions: *Boltzmann, Andrey Markov, Mark I. Freidlin, Alexander D. Wentzell, John Nash, & Brian Arthur, among others.