Active Caustics

Statistical Physics and Complexity Group meeting

Active Caustics

  • Event time: 3:00pm until 4:00pm
  • Event date: 14th November 2023
  • Speaker: (Indian Institute of Science, Bangalore)
  • Location: Online - see email.

Event details

We show that self-propelled particles (SPPs) with no mechanical inertia form caustics when advected by vortical flow. This seemingly inertial behaviour is a result of the persistence of their motion in the direction of their intrinsic orientation. We establish that SPPs form caustics at a critical distance from the origin of a single point vortex, and in straining regions when advected by 2D Navier-Stokes turbulence. This mechanism for singularly high local concentrations in a macroscopically dilute suspension of zero-Re swimmers has potential implications for communication and sexual reproduction. This work was done in collaboration with Rahul Chajwa, Rajarshi, and Rama Govindarajan; see arXiv:2310.01829.

Event resources