BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Blaise Gouteraux (École Polytechnique) DTSTART:20210108T110000Z DTEND:20210108T120000Z DTSTAMP:20260513T222338Z UID:CCTP_HEP/30 DESCRIPTION:Title: Hydrodynamic diffusion and its breakdown near AdS2 fixed points\nby Blaise Gouteraux (École Polytechnique) as part of CCTP HEP Seminars\n\n\n Abstract\nHydrodynamics provides a universal description of interacting qu antum field theories at sufficiently long times and wavelengths\, but brea ks down at scales dependent on microscopic details of the theory. We use g auge-gravity duality to investigate the breakdown of diffusive hydrodynami cs in two low temperature states dual to black holes with AdS2 horizons. W e find that the breakdown is characterized by a collision between the diff usive 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 se t by infra-red properties of the theory. The absolute values of the freque ncy and wavevector at the collision (ωeq and keq) provide a natural chara cterization 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. \n LOCATION:https://researchseminars.org/talk/CCTP_HEP/30/ END:VEVENT END:VCALENDAR