English

Is it true that no mathematical relation exists between the Navier-Stokes equations and the multifractal model?

Fluid Dynamics 2026-04-15 v2 Chaotic Dynamics

Abstract

Contrary to accepted turbulence folklore, which holds that no mathematical relation exists between the Navier-Stokes equations (NSEs) and the multifractal model (MFM) of Parisi and Frisch, we develop a theory that reconciles the MFM with Leray's weak solutions of Navier-Stokes analysis. From a combination of Euler invariant scaling and the NSEs set in a three-dimensional box of size LL, we also derive the Paladin-Vulpiani inverse scale ηh,pav\eta_{h,pav}, which is related to the Reynolds number Re\mathit{Re} by Lηh,pav1=Re1/(1+h)L\eta_{h,pav}^{-1} = \mathit{Re}^{1/(1+h)}, and which acts as a mediator between the two theories. This is achieved by considering L2mL^{2m}-norms of the velocity gradient to find a correspondence between mm and the local scaling exponent hh in the multifractal model. The parameter mm acts as if it were the sliding focus control on a telescope which allows us to zoom in and out on different structures. The range 1m1 \leqslant m \leqslant \infty is equivalent to 2/3hmin1/3-2/3 \leqslant h_{min} \leqslant 1/3, which lies precisely in the region where Bandak et al. (2022, 2024) have suggested that thermal noise makes the NSEs inadequate and generates spontaneous stochasticity. The implications of this are discussed.

Keywords

Cite

@article{arxiv.2603.19125,
  title  = {Is it true that no mathematical relation exists between the Navier-Stokes equations and the multifractal model?},
  author = {John D. Gibbon and Dario Vincenzi},
  journal= {arXiv preprint arXiv:2603.19125},
  year   = {2026}
}

Comments

13 pages, 2 figures