Biography
Greg J Stephens is an associate professor of physics at the Vrije Universiteit Amsterdam and an adjunct professor at OIST Graduate University in Japan, In 2022 he was selected as a fellow of the American Physical Society. He received his PhD in theoretical physics from the University of Maryland with a dissertation in general relatively under the guidance of Bei-Lok Hu. He held postdoctoral positions at Los Alamos National Laboratory with Wojciech Zurek and Garret Kenyon, and, after a change in research direction to the physics of living systems, with William Bialek at Princeton University. Centered on organism-scale biophysics, his research combines dynamical systems, statistical physics and information theory to understand animals in natural motion.
Research description
Work in the Stephens group seeks to be as precise about the laws and principles that govern the emergent scale of entire organisms as we are about the molecules, cells and circuits from which behaviour is ultimately derived. We create and explore models and their consequences, but also work in the “inverse”, were we develop theory-guided approaches to interrogate (new, ) precision measurements and infer important concepts directly from data. This inverse approach provides an essential component both for a quantitative understanding of living systems, but also generally to complex systems, for which we may not know a priori the right dynamical model, universality class and order parameter(s), or even the most relevant theoretical concepts. We find the dynamics of behavior to be extremely fertile ground for both theoretical and computational explorations seeking organizing principles of living and other complex systems, and our particular focus ranges from the nematode worm C. elegans, to the social behavior of zebrafish and squid, and even the collective dynamics of honey bee colonies.
Selected Publications
A Carlos Costa, T Ahamed, D Jordan & GJ Stephens, Maximally predictive states: from partial observations to long timescales (2022); bioRxiv https://doi.org/10.1101/2021.05.26.445816; arXiv:2105.12811
L Hebert, T Ahamed, A Carlos Costa, L O’Shaughnessy & GJ Stephens, WormPose: Image synthesis and convolutional networks for pose estimation in C. elegans. PLOS Comp Bio 17(4):e1008914 (2021); https://doi.org/10.1371/journal.pcbi.1008914; bioRxiv https://doi.org/10.1101/2020.07.09.193755
K Bozek, L Hebert Y Portugal, AS Mikheyev & GJ Stephens, Markerless tracking of an entire honey bee colony. Nat Comm 12, 1733 (2021); https://doi.org/10.1038/s41467-021-21769-1; bioRxiv https://doi.org/10.1101/2020.03.26.007302
T Ahamed, A Carlos Costa & GJ Stephens, Capturing the continuous complexity of behavior in C. elegans. Nat Phys https://doi.org/10.1038/s41567-020-01036-8 (2020); bioRxiv https://doi.org/10.1101/827535. See also J Loveless & B Webb, Chaotic worms, Nat. Phys News & Views (2020); https://doi.org/10.1038/s41567-020-01058-2
GJ Stephens, B Johnson–Kerner, W Bialek & WS Ryu, Dimensionality and dynamics in the behav- ior of C. elegans. PLoS Comp Bio 4, e1000028 (2008); https://doi.org/10.1371/journal.pcbi.1000028; arXiv:0705.1548; See also Faculty of 1000 evaluations: I Couzin: 2009. F1000.com/1109020, L Maler: 2008. F1000.com/1109020
For a complete publication list see Google scholar page for Greg Stephens
