Scaling behavior of non-equilibrium measures in soft biological assemblies Chromosome

• Applicant: Professor Dr. Chase Broedersz
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: from 2019 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 418389167

Living matter operates far from thermodynamic equilibrium. Prominent examples include chromosomes and cytoskeletal networks, where molecular scale activity of enzymatic proteins drives large-scale non-equilibrium fluctuations. However, a general approach to determine the microscopic properties of active driving from experimentally accessible mesoscopic measurements remains elusive. Recently, we showed that the active nature of living matter can be determined non-invasively by observing the steady-state stochastic dynamics of mesoscopic degrees of freedom using time-lapse microscopy experiments. The non-equilibrium dynamics of these systems can manifest as circulating probability currents in a phase space of mesoscopic coordinates indicating broken detailed balance. Our central objective is to provide a theoretical understanding that reveals how to use such mesoscopic non-equilibrium measures to extract quantitative information that characterizes the microscopic properties of the active driving in soft biological assemblies.To achieve this objective, we will develop a stochastic theoretical framework for active soft assemblies. Using this framework, we will provide a theoretical description of the spatial scaling behavior of broken detailed balance in internally driven systems. In particular, we use spring lattices with active driving to elucidate how characteristic features of the system, such as the system’s architecture or the properties of the active driving forces, determine the scaling of non-equilibrium measures. Our work aims to provide new ways in which stochastic non-equilibrium dynamics in biological assemblies are measured, analysed, and interpreted, leading to a potentially new approach for the physical characterization of living matter in cells and tissue.

• DFG Programme: Research Grants
• International Connection: USA
• Cooperation Partner: Professor Ming Guo