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Related papers: Comment on 'Conformal invariance of the zero-vorti…

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The recent claim by Grebenev et al. [J. Phys. A: Math. Theor. 50, 435502 (2017)] that the inviscid 2D Lundgren-Monin-Novikov (LMN) equations on a zero vorticity characteristic naturally would reveal local conformal invariance when only…

Fluid Dynamics · Physics 2020-08-13 Michael Frewer , George Khujadze

Although the current Reply by Grebenev et al. (2021a) makes their original analysis in Grebenev et al. (2017) more transparent, the actual problem remains. Their claim to have analytically proven conformal invariance in 2D turbulence for a…

Fluid Dynamics · Physics 2021-10-22 Michael Frewer , George Khujadze

The recent study by Waclawczyk et al. [Phys. Rev. Fluids 6, 084610 (2021)] on conformal invariance in 2D turbulence is misleading as it makes three incorrect claims that form the core of their work. We will correct these claims and put them…

Fluid Dynamics · Physics 2021-12-06 Michael Frewer , George Khujadze

The recent study by Waclawczyk et al. [J. Phys. A: Math. Theor. 50, 175501 (2017)] possesses three shortcomings: (i) The analysis misses a key aspect of the LMN equations which makes their Lie-group symmetry results incomplete. In…

Fluid Dynamics · Physics 2022-05-03 Michael Frewer , George Khujadze , Holger Foysi

We present an overview of recent works on the statistical description of turbulent flows in terms of probability density functions (PDFs) in the framework of the Lundgren-Monin-Novikov (LMN) hierarchy. Within this framework, evolution…

Fluid Dynamics · Physics 2013-03-19 R. Friedrich , A. Daitche , O. Kamps , J. Lülff , M. Voßkuhle , M. Wilczek

We present a critical examination of the recent article by Waclawczyk et al. (2014) which proposes two new statistical symmetries in the classical theory for turbulent hydrodynamic flows. We first show that both symmetries are unphysical in…

Fluid Dynamics · Physics 2016-10-04 Michael Frewer , George Khujadze , Holger Foysi

We show that a simple modification of the Lagrangian proposed by Padmanabhan in the paper [Mod. Phys. Lett. A 33, 1830005 (2018), arXiv:1712.07328] leads to the most general dynamical invariant in [Ray and Reid, Phys. Lett. A 71, 317…

Mathematical Physics · Physics 2018-08-14 A. Gallegos , H. C. Rosu

We show that Lorentz symmetry is generally absent for noncommutative (abelian) gauge theories and obtain a compact formula for the divergence of the Noether currents that allows a throughout study of this instance of symmetry violation. We…

High Energy Physics - Theory · Physics 2011-11-10 Alfredo Iorio

In Haller and Beron-Vera (2013) we developed a variational principle for the detection of coherent Lagrangian vortex boundaries. The solutions of this variational principle turn out to be closed null-geodesics of the Lorentzian metric…

Atmospheric and Oceanic Physics · Physics 2015-06-19 G. Haller , F. J. Beron-Vera

We study conformal invariance of vorticity clusters in weakly compressible two-dimensional turbulence at low Mach numbers. On the basis of very high resolution direct numerical simulation we demonstrate the scaling invariance of the inverse…

Fluid Dynamics · Physics 2020-08-19 Leonardo Puggioni , Alexei G. Kritsuk , Stefano Musacchio , Guido Boffetta

Of all real Lagrangian--Grassmannians $LG(n,2n)$, only $LG(2,4)$ admits a distinguished (Lorentzian) conformal structure and hence is identified with the indefinite M\"obius space $S^{1,2}$. Using Cartan's method of moving frames, we study…

Differential Geometry · Mathematics 2017-11-20 Dennis The

In this note we contribute two results to the theory of the $2D$ Euler equations in vorticity form on the full plane. First, we establish a generalized Lagrangian representation of weak (in general measure-valued) solutions, which includes…

Analysis of PDEs · Mathematics 2025-10-07 Marco Rehmeier , Marco Romito

Recently Perez et al [arXiv:1209.2011] wrote on the spectral slope of MHD turbulence claiming that it is consistent with -3/2. This work contains a number of errors, factual inaccuracies and puzzling methods in the interpretation of…

Astrophysics of Galaxies · Physics 2013-02-01 Andrey Beresnyak

We introduce the Lorentzian path integral of nonlocal quantum gravity. After introducing the functional measure, the Faddeev-Popov sector and the field correlators, we move to perturbation theory and describe Efimov analytic continuation of…

High Energy Physics - Theory · Physics 2024-08-05 Gianluca Calcagni , Leonardo Modesto

In this note, we establish Yudovich's existence and uniqueness result for bounded (as well as mildly unbounded) vorticity weak solution of the two-dimensional incompressible Euler equations. As a biproduct of our proof, we establish some…

Analysis of PDEs · Mathematics 2025-09-26 Theodore D. Drivas , Joonhyun La

We present a search for conformal invariance in vorticity isolines of two-dimensional compressible turbulence. The vorticity is measured by tracking the motion of particles that float at the surface of a turbulent tank of water. The…

Chaotic Dynamics · Physics 2011-10-13 S. Stefanus , J. Larkin , W. I. Goldburg

We consider uniformly rotating incompressible Euler and Navier-Stokes equations. We study the suppression of vertical gradients of Lagrangian displacement ("vertical" refers to the direction of the rotation axis). We employ a formalism that…

Analysis of PDEs · Mathematics 2007-05-23 Peter Constantin

We consider deformations of singular Lagrangian varieties in symplectic spaces. We show the coherence of the direct image sheaves of relative infinitesimal Lagrangian deformations. Using this result, we prove that, under some assumptions, a…

Algebraic Geometry · Mathematics 2007-05-23 Mauricio D. Garay

This paper is concerned with six variational problems and their mutual connections: The quadratic Monge-Kantorovich optimal transport, the Schr\"odinger problem, Brenier's relaxed model for incompressible fluids, the so-called Br\"odinger…

Analysis of PDEs · Mathematics 2019-08-09 Aymeric Baradat , Léonard Monsaingeon

In Lagrangian turbulence one is faced with the puzzle that 2D Navier-Stokes flows are nearly as intermittent as in three dimensions although no intermittency is present in the inverse cascade in 2D Eulerian turbulence. In addition, an…

Fluid Dynamics · Physics 2007-05-23 Rudolf Friedrich , Rainer Grauer , Holger Homann , Oliver Kamps
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