"The Physics of Active Matter" by Cristina Marchetti (UCSB)

Thursday, November 7, 2019 - 4:00pm
Physics and Astronomy Colloquium

Thursdays, 4:00-5:00 pm

1-434 Physics and Astronomy (map)
Reception from 3:15-3:30 p.m.
 (unless otherwise posted)

Guest Speaker: Cristina Marchetti (University of California, Santa Barbara)

Talk Title:  “The Physics of Active Matter”

Abstract:  Assemblies of interacting self-driven entities form soft active materials with intriguing collective behavior and mechanical properties. Examples abound in nature on many scales, from the flocking of birds to cell migration in morphogenesis. They also include synthetic systems, from engineered microswimmers to self-catalytic colloids and autonomously propelled liquid crystals.  What unifies these systems is that they are driven out of equilibrium by dissipative processes that act on each individual particle, hence break the time reversal symmetry of the dynamics at the microscale. This results in surprising behavior. For instance, active fluids flow with no externally applied driving forces, active gases do not fill their container, and active particles spontaneously organize when passive ones would not. Since time reversal symmetry of the microdynamics and the associated detailed balance of forward and reverse processes are built into the foundation of equilibrium statistical physics, the description of active systems poses a new theoretical challenge.  In this talk I will discuss the physics of active matter with examples from both the living and non-living worlds. I will show that by combining minimal physical models with continuum theory and simulations we are making advances towards capturing quantitatively the laws of spontaneous organization of active systems.  This theoretical progress has implication for both formulating design principles for new smart materials and understanding cellular and multicellular organization.

For more information, contact Yaroslav Tserkovnyak

We thank the following people for their contributions to the wine fund for the post-colloquium reception:
Professors Katsushi Arisaka, Andrea Ghez, Karoly Holczer, Huan Huang, HongWen Jiang, Per Kraus, Alexander Kusenko, Matthew Malkan, Mayank Mehta, Warren Mori, Ni Ni, Seth Putterman, Yaroslav Tserkovnyak, Vladimir Vassiliev, Shenshen Wang, and Nathan Whitehorn.

1-434 PAB