Overcoming obstacles in nonequilibrium holography

Understand

We study universal spatial features of certain non-equilibrium steady states corresponding to flows of strongly correlated fluids over obstacles.

• This allows us to predict universal spatial features of far-from-equilibrium systems, which in certain interesting cases depend cleanly on the hydrodynamic transport coefficients of the underlying theory, such as $\eta/s$, the shear viscosity to entropy density ratio.
• In this work we give a purely field-theoretical definition of the spatial collective modes identified earlier and proceed to demonstrate their usefulness in a set of examples, drawing on hydrodynamic theory as well as holographic duality.
• We extend our earlier treatment by adding a finite chemical potential, which introduces a qualitatively new feature, namely damped oscillatory behavior in space.