Field Theories of active and driven matter

02.05.2019 to 03.05.2019
Jonathan Keeling, Silke Henkes, Stephen Watson, Davide Marenduzzo

The Higgs Centre for Theoretical Physics


When energy is continuously fed into a system the states of matter, large scale structures it can form, and the collective dynamics it undergoes are far richer than for a system in thermal equilibrium.  In the last decade, two distinct and separate communities have developed addressing aspects of this problem in quantum and in classical systems. In the context of quantum systems, work on the collective behaviour of driven-dissipative systems has explored Bose-Einstein condensation of particles with finite lifetime, and the possibility of creating “crystals of light”, using microwave or optical photons to simulate phases of matter.  The classical context in which such problems are studied is that of active matter, which explores how the local energy input from individual living organisms creates a new class of fluids, with applications including the flocking of animal swarms, biological tissue dynamics, and engineered active colloids.

In both these fields, a central challenge is to understand how large scale behaviour emerges from the microscopic details of the theory, and to classify the forms of behaviour that are possible.  Such a goal, echoing the concepts of universality known from equilibrium critical phenomena, remains an open challenge. While classification of some types of behaviour was summarised in the canonical 1977 review of Hohenberg and Halperin on dynamical critical phenomena, the work of the last decade has shown there exist wide varieties of behaviour not captured by the approach presented there.   Field theoretic approaches are a key tool in abstracting the effective long wavelength description from a microscopic theory. Moreover, they provide a natural route to renormalization group approaches, extracting critical behaviour at large scales. Such approaches are applicable both in quantum and classical problems, via the Schwinger-Keldysh and Martin-Siggia-Rose path integral approaches respectively.

This meeting aims to bring together these two distinct communities, inviting a core of those researchers whose work has crossed the divide of quantum and classical, as well as key researchers focussed on the two separate areas.  In order to ensure real connections are developed, speakers will be asked to provide a pedagogical introduction to their talks, aimed at addressing the full range of participants of the meeting.

This meeting is supported both by the Higgs Centre and by the EPSRC Network on Emergence and Physics Far From Equilibrium. Members of this network can claim for travel expenses for attending this meeting.

Registration for this event will open in December