Birth, Death, and Flight: The Hydrodynamics of Malthusian Flocks

I’ll present the hydrodynamic theory of “Malthusian Flocks”: moving aggregates of self-propelled entities (e.g., organisms, cytoskeletal actin, microtubules in mitotic spindles) that reproduce and die. Long-ranged order is possible in these systems, even in spatial dimension $d=2$. I’ll present results for both two and three dimensional Malthusian flocks; the latter required the first full blown dynamical renormalization treatment of a flocking system in its ordered phase.