The role of Weyl symmetry in hydrodynamics

Understand

This article is dedicated to the analysis of Weyl symmetry in the context of relativistic hydrodynamics.

• Here is discussed how this symmetry is properly implemented using the prescription of minimal coupling: $\partial\to \partial +\omega \mathcal{A}$.
• It is shown that this prescription has no problem to deal with curvature since it gives the correct expressions for the commutator of covariant derivatives.
• In the hydrodynamics the Weyl gauge connection emerges from the degrees of freedom of the fluid: it is a combination of the expansion and entropy gradient.