Time: 3:30 pm
Location: ABB 102
Guest: Dr. Daniel Sussman
Emory College of Arts and Sciences
Title: Nonreciprocal forces and exceptional phase transitions in models of flocking
How is the behavior of non-equilibrium systems different from equilibrium ones, what new collective motion and pattern formation can be found in living as opposed to simply “active” systems? This talk will approach these questions within a framework -- Toner-Tu hydrodynamics -- meant to describe flocking organisms as a type of active polar aligning matter. I will show how the aligning interactions of coarse-grained representations of flocking agents correspond to nonreciprocal forces, i.e., forces that violate Newton’s third law. These forces can lead to qualitatively new collective behaviors, which I will demonstrate in the context of classic microscopic numerical models. Finally, I will connect these ideas to both long-standing puzzles in the field and speculations about actual flocking and schooling behaviors observed in nature.