*Michael Shelley*

*Lilian and George Lyttle Professor of Applied MathematicsProfessor of Mathematics and Neural Science Co-Director, Applied Mathematics Laboratory Courant Institute of Mathematical SciencesNew York University*

Active fluids are complex fluids with active microstructure that create non-thermodynamic stresses even in the absence of external forcing.

A typical example of such a out-of-equilibrium system is a bacterial bath where stresses created by bacterial swimming can create large-scale chaotic mixing flows. Other examples arise in cellular biophysics where the interactions of biopolymers with motor-proteins can yield "active nematic" states of matter. I will discuss the mathematical modeling and simulation of these systems by building Doi-Onsager descriptions based upon a microscopic conception of the microstructural dynamics.