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Nuclear Physics Seminar - Michael McNelis (The Ohio State University) - "Hydrodynamic Generator in the Relaxation Time Approximation"

Michael McNelis (The Ohio State University), 9/9/20 Nuclear Physics Seminar speaker
September 9, 2020
4:00PM - 5:00PM
Zoom seminar

Date Range
Add to Calendar 2020-09-09 16:00:00 2020-09-09 17:00:00 Nuclear Physics Seminar - Michael McNelis (The Ohio State University) - "Hydrodynamic Generator in the Relaxation Time Approximation" Recently, the heavy-ion physics community has been interested in understanding the emergence of hydrodynamic behavior in far-from-equilibrium fluids (e.g. quark-gluon plasma formed in heavy-ion collisions). Conventionally, hydrodynamics is a small gradient expansion that should only work for near-equilibrium fluids. However, the success of viscous hydrodynamic simulations of heavy-ion collisions forces us to revisit this assumption. Here, we present a new way of deriving hydrodynamics from the Boltzmann equation in the relaxation time approximation. Our approach expands the Green’s function of the Boltzmann distribution to generate the hydrodynamic gradient series along with nonperturbative corrections. These nonperturbative terms strongly suppress high-order viscous corrections to the energy-momentum tensor of conformal systems subject to Bjorken flow. From the new expansion, we also derive i) a set of hydrodynamic equations capable of modeling kinetic systems far from equilibrium and ii) an alternative method for constructing the hydrodynamic attractor in Bjorken expansion. Zoom link: https://osu.zoom.us/j/93062863602?pwd=anZmS25HMDdvYTNxamVZWjlBMXloQT09 Passcode: 145084           Zoom seminar Department of Physics physics@osu.edu America/New_York public

Recently, the heavy-ion physics community has been interested in understanding the emergence of hydrodynamic behavior in far-from-equilibrium fluids (e.g. quark-gluon plasma formed in heavy-ion collisions). Conventionally, hydrodynamics is a small gradient expansion that should only work for near-equilibrium fluids. However, the success of viscous hydrodynamic simulations of heavy-ion collisions forces us to revisit this assumption. Here, we present a new way of deriving hydrodynamics from the Boltzmann equation in the relaxation time approximation. Our approach expands the Green’s function of the Boltzmann distribution to generate the hydrodynamic gradient series along with nonperturbative corrections. These nonperturbative terms strongly suppress high-order viscous corrections to the energy-momentum tensor of conformal systems subject to Bjorken flow. From the new expansion, we also derive i) a set of hydrodynamic equations capable of modeling kinetic systems far from equilibrium and ii) an alternative method for constructing the hydrodynamic attractor in Bjorken expansion.

Zoom link: https://osu.zoom.us/j/93062863602?pwd=anZmS25HMDdvYTNxamVZWjlBMXloQT09

Passcode: 145084