Viscosity of an ideal relativistic quantum fluid: A perturbative study

Understand

We show that a quantized ideal fluid will generally exhibit a small but non-zero viscosity due to the backreaction of quantum soundwaves on the background.

• We use an effective field theory expansion to estimate this viscosity to first order in perturbation theory.
• We discuss our results, and whether this estimate can be used to obtain a more model-independent estimate of the "quantum bound" on the viscosity of physical systems