Recent experiments on confluent layers of epithelial cells and vibrated granular media have motivated interest in the behavior of active systems at high density, where the interplay of steric repulsion and activity can yield active glassy or jammed states. In this talk I will discuss the behavior of dense collections of self-propelled particles in two dimensions. Two specific results will be highlighted: (i) the suppression of motility due to steric repulsion yields macroscopic phase separation in the absence of any aligning or attractive interaction; and (ii) confinement yields jammed active states where the dynamics is dominated by spatio-temporal heterogeneities reminiscent of glassy systems.
Lunch @ 11:45, talk @ 12-1:00