DIEP seminar by Stefan Thurner
Towards a statistics of driven complex systems
Most complex systems are not in equilibrium but driven. We argue that driven systems can be understood by so-called sample space reducing (SSR) processes. They provide an intuitive understanding of the origin and ubiquity of fat-tailed distributions in complex systems, power-laws in particular. SSR processes are mathematically simple and offer an alternative to Boltzmann-equation based approaches to non-equilibrium systems.
We show that in many situations the statistics is determined by the details of the driving process and does not depend on the specific relaxation dynamics. Simple (homogeneous) driving strategies universally lead to Zipf’s law and exact power laws. Other driving processes results in exponential, Gamma, normal, Weibull, Gompertz, and Pareto distributions. We discuss a number of examples of SRR processes, including fragmentation processes, language formation, cascading and search processes, as well as a classic in physics: inelastical collisions.
If you wish to attend this seminar online, please send an email to w.merbis@uva.nl to receive the zoom-link.
Stefan is full professor for Science of Complex Systems at the Medical University of Vienna, where he chairs Section for Science of Complex Systems. Since 2015 he serves as the president of the Complexity Science Hub Vienna, an Institution dedicated to the science of complex systems in Europe.
Stefan obtained a PhD in theoretical physics from the Technical University of Vienna and a PhD in economics from the University of Vienna. He held postdoc positions at Humboldt University of Berlin and Boston University before joining the faculty of the University of Vienna and later Medical University. Stefan started his career with contributions to theoretical particle physics and gradually shifted his research focus to the understanding of complex systems.
Stefan has published more than 200 scientific articles in theoretical physics (topological excitations in quantum field theories, statistics and entropy of complex systems), applied mathematics (wavelet statistics, fractal harmonic analysis, anomalous diffusion), network theory, evolutionary dynamics, life sciences (network medicine, gene regulatory networks, bioinformatics, heart beat dynamics, cell motility), economics and finance (price formation, regulation, systemic risk) and in social sciences (opinion formation, bureaucratic inefficiency, collective human behavior, efficiency of healthcare systems). He holds two patents.
His work has been covered by media such as the New York Times, BBC world, Nature, New Scientist, Physics World, and is featured in more than 500 newspaper, radio and television reports. Stefan was elected Austrian “scientist of the year” in 2018.