Symmetry, Thermodynamics and Topology in Active Matter

Coordinators: Mark Bowick, Mike Cates, Nikta Fakhri, Cristina Marchetti, and Sriram Ramaswamy

Active systems are collections of interacting entities that are individually self-driven and thus carry a dissipative arrow of time. Living matter from subcellular structures to cells to tissue is the inspiration for defining this distinctive class of materials. Active matter also includes a variety of synthetic systems that display spontaneous assembly and exhibit life-like behavior.

Active systems break detailed balance at the microscale. Formulating the statistical physics of active systems thus requires conceptually new approaches. The program will bring together researchers from a broad range of disciplines to address emerging questions and spearhead new directions. Key questions to be probed include: can we formulate constitutive laws of the mechanics and rheology of active systems and how are these affected by confinement and boundaries? Can stochastic thermodynamics offer a framework for quantifying dissipation in active matter and understanding noise and metabolic consumption in living systems? What is the role of topological excitations and topologically protected states in active matter - can they serve a biological function or provide seeds for active assembly? Can we go beyond minimal models to formulate theories with predictive power for active systems with more complex rules, such as collections of cells or microorganisms that are not only motile, but subject to signaling, division, programmed death, mechano-sensing, and other self-regulated active processes? Can we use the understanding of these more complicated interactions to program the assembly of active materials with new functionalities?