In this paper at the at the beginning of the last paragraph on p.2 it is said, that the Euler equations, which are an infinite Reynolds number limit of the Navier-Stokes equations, arise as an RNG fixed point. This fixed point is said to be non-unique for a system witn N mixing species, because it can be choosen from an N+1 dimensional parameter space spanned by N-1 dimensionless mass diffusivities, the dimensionless thermal diffusivity (or Prandtl number) and the dimensionless ratio of the anisotropic and isotropic viscosity.
About this issue I have several closely related questions:
What kind of fixed point is this when considering a classification into Gaussian/interacting, trivial/nontrivial, etc fixed points
What is the expected behaviour of the RG flow around this fixed point?
Is the non-uniqueness of this fixed point the same kind of non-uniquenes as the one described on p67 if this paper, which explains that the presence of redundant marginal operators can lead to a whole line of physically equivalent fixed points? If this way of analyzing a fixed point can be applied in my example, would the Euler equations fixed point then correspond to some kind of an N+1 dimensional surface of fixed points where the mass diffusivities, the Prandtl number, and the ratio of the anisotropic and isotropic viscosity play the role of such redundant marginal operators?