Valley Prize (2022): TBD

I will describe new universality classes of hydrodynamic phenomena and non-equilibrium fixed points which arise in constrained many-body systems.  These new theories are inspired by exotic physical systems with "fracton" excitations.  I will highlight how modern methods from effective field theory are leading us to a systematic understanding and classification of new universality classes of constrained hydrodynamics and how -- in turn -- these new fluids might lead us to a better understanding of hydrodynamics more generally. 

As an interesting example of a new universality class, I will describe a "fractonic" generalization of the non-equilibrium Kardar-Parisi-Zhang fixed point that can exist below four spatial dimensions. This non-equilibrium fixed point, and others, arise out of a fundamental instability of the hydrodynamics of a (constrained) fluid at rest.

One of these universality classes -- the subdiffusion of charge in the presence of dipole conservation -- has already been experimentally observed in ultracold atoms in a tilted optical lattice.  Time permitting, I will suggest ideas for how to discover further universality classes in experiments.