Speaker
Description
The observation, in hadronic collisions, of "ideal fluid" type behavior in systems of a
comparatively small number of particles, presents a conceptual puzzle, since the
way we usually derive hydrodynamics is via approximating "many" particles as a
continuum. I will argue that making sense of this requires re-deriving relativistic
hydrodynamics as a "bottom-up" theory, with no reference to microscopic physics
except the local emergence of a thermalized system. We attempt to do this using
basic statistical mechanics, and find the appearance of a gauge-like redundancy
hidden within relativistic dissipative hydrodynamics, arising from the fluctuation-
dissipation theorem. This might lead to the apparently counter-intuitive conclusion
that in the small viscosity limit it might indeed be that smaller systems could
thermalize faster via an "inverse attractor" mechanism.
Based on https://arxiv.org/abs/2109.06389
