Hydrodynamic diffusion and its breakdown near AdS2 fixed points

Abstract: Hydrodynamics provides a universal description of interacting quantum field theories at sufficiently long times and wavelengths, but breaks down at scales dependent on microscopic details of the theory. We use gauge-gravity duality to investigate the breakdown of diffusive hydrodynamics in two low temperature states dual to black holes with AdS2 horizons. We find that the breakdown is characterized by a collision between the diffusive pole of the retarded Green's function with a pole associated to the AdS2 region of the geometry, such that the local equilibration time is set by infra-red properties of the theory. The absolute values of the frequency and wavevector at the collision (ωeq and keq) provide a natural characterization of all the low temperature diffusivities D of the states via D=ωeq/keq^2 where ωeq=2πΔT is set by the temperature T and the scaling dimension Δ of an infra-red operator. We confirm that these relations are also satisfied in an SYK chain model in the limit of strong interactions.

general relativity and quantum cosmologyHEP - phenomenologyHEP - theorymathematical physics

Audience: researchers in the topic

CCTP HEP Seminars

Series comments: Description: Seminars in high energy physics

Weekly HEP Seminars in the broad spectrum of High Energy Physics at University of Crete.

Recordings of past seminars can be found at conference.physics.uoc.gr/b/hep-kzk-2ad