Non-hydrodynamic transport in trapped unitary Fermi gases

TL;DR

This paper explores the presence of non-hydrodynamic modes in strongly coupled fluids, specifically in trapped unitary Fermi gases, suggesting these modes influence transient dynamics beyond traditional hydrodynamic behavior.

Contribution

It introduces the idea that non-hydrodynamic modes, known from kinetic theory and gauge/gravity duality, may be observed in cold Fermi gases near unitarity, extending understanding of their transient dynamics.

Findings

Hints of non-hydrodynamic modes in experimental data

Analysis of these modes in two and three-dimensional gases

Discussion of signatures from kinetic theory and gauge/gravity duality

Abstract

Many strongly coupled fluids are known to share similar hydrodynamic transport properties. In this work we argue that this similarity could extend beyond hydrodynamics to transient dynamics through the presence of non-hydrodynamic modes. We review non-hydrodynamic modes in kinetic theory and gauge/gravity duality and discuss their signatures in trapped Fermi gases close to unitarity. Reanalyzing previously published experimental data, we find hints of non-hydrodynamic modes in cold Fermi gases in two and three dimensions.