Flatiron Institute Seminar Series: Scott Weady

Title: From micro to macroscopic models of living matter

Abstract: Living systems typically consist of a large number of active, interacting constituents. Whether mediated through fluid flows, chemical signaling, or collision forces, their interactions can lead to fascinating collective, self-organizing behavior and pattern formation. Simulating and analyzing such systems is challenging due to their many coupled degrees of freedom. In this talk, we present methods for simulating many-particle dynamics, especially the challenging task of resolving collisions, and discuss coarse-graining procedures for deriving corresponding continuum models. We consider two canonical problems: suspensions of swimming microorganisms and growing bacterial colonies. Being able to simulate large systems (here on the order of a million particles) allows us to approach biologically relevant scales and uncover new phenomena, as well as assess continuum models and their limitations.