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Related papers: Lagrangian Description in the context of Emergent …

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Lagrangian turbulence lies at the core of numerous applied and fundamental problems related to the physics of dispersion and mixing in engineering, bio-fluids, atmosphere, oceans, and astrophysics. Despite exceptional theoretical,…

Traditional approaches to the study of the dynamics of spacetime curvature in a very real sense hide the intricacies of the nonlinear regime. Whether it be huge formulae, or mountains of numerical data, standard methods of presentation make…

General Relativity and Quantum Cosmology · Physics 2013-05-30 Kayll Lake

We show that, for two-dimensional space-periodic incompressible flow, the solution can be evaluated numerically in Lagrangian coordinates with the same accuracy achieved in standard Eulerian spectral methods. This allows the determination…

Chaotic Dynamics · Physics 2009-11-13 T. Matsumoto , J. Bec , U. Frisch

We establish the longtime existence and convergence results of the mean curvature flow of entire Lagrangian graphs in Pseudo-Euclidean space which is related to Logarithmic gradient flow.

Analysis of PDEs · Mathematics 2010-03-12 R. L. Huang

We summarize the arguments that space and time are likely to be emergent notions; i.e. they are not present in the fundamental formulation of the theory, but appear as approximate macroscopic concepts. Along the way we briefly review…

High Energy Physics - Theory · Physics 2017-08-23 Nathan Seiberg

Phase-space Lagrangian dynamics in ideal fluids (i.e, continua) is usually related to the so-called {\it ideal tracer particles}. The latter, which can in principle be permitted to have arbitrary initial velocities, are understood as…

Fluid Dynamics · Physics 2015-05-13 Marco Tessarotto , Claudio Cremaschini , Massimo Tessarotto

We study the one-point probability distribution functions (PDFs) of the peculiar velocity and the density fluctuation in a cosmological fluid. Within the perturbative approach to the structure formation scenario, the effect of ``pressure''…

Astrophysics · Physics 2009-11-11 Takayuki Tatekawa

We introduce Lagrange2D, a Mathematica package for analysis and characterization of complex fluid flows using Lagrangian transport metrics. Lagrange2D includes built-in functions for integrating ensembles of trajectories subject to…

Fluid Dynamics · Physics 2019-08-05 William Gilpin

We review some recent results on the mean curvature flows of Lagrangian submanifolds from the perspective of geometric partial differential equations. These include global existence and convergence results, characterizations of first-time…

Differential Geometry · Mathematics 2011-04-19 Mu-Tao Wang

This article reviews several recently developed Lagrangian tools and shows how their combined use succeeds in obtaining a detailed description of purely advective transport events in general aperiodic flows. In particular, because of the…

Fluid Dynamics · Physics 2012-08-22 Carolina Mendoza , Ana M. Mancho

We develop an analytic formalism and derive new exact relations that express the short-time dispersion of fluid particles via the single-time velocity correlation functions in homogeneous isotropic and incompressible turbulence. The…

Chaotic Dynamics · Physics 2015-08-04 Gregory Falkovich , Anna Frishman

This paper reviews the essential physics of gravitational instability in a Robertson-Walker background spacetime. Three approaches are presented in a pedagogical manner, based on (1) the Eulerian fluid equations, (2) the Lagrangian…

Astrophysics · Physics 2007-05-23 Edmund Bertschinger

The reduction of dimensionality of physical systems, specially in fluid dynamics, leads in many situations to nonlinear ordinary differential equations which have global invariant manifolds with algebraic expressions containing relevant…

Fluid Dynamics · Physics 2021-06-23 Nicolas E. Sujovolsky , Pablo D. Mininni

We investigate the appropriateness of the use of different Lagrangians to describe various components of the cosmic energy budget, discussing the degeneracies between them in the absence of nonminimal couplings to gravity or other fields,…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-23 V. M. C. Ferreira , P. P. Avelino , R. P. L. Azevedo

We study the Lagrangian trajectories of statistically isotropic, homogeneous, and stationary divergence free spatiotemporal random vector fields. We design this advecting Eulerian velocity field such that it gets asymptotically rough and…

Fluid Dynamics · Physics 2020-07-08 Jason Reneuve , Laurent Chevillard

It is shown that the addition of a non-linear term to the Lagrangian of the electromagnetic field yields a fluid with an asymptotically super-negative equation of state, causing an accelerated expansion of the universe. Some general…

Astrophysics · Physics 2009-11-10 M. Novello , S. E. Perez Bergliaffa , J. Salim

We prove short-time existence for the Einstein-Euler-Entropy system for non-isentropic fluids with data in uniformly local Sobolev spaces. The cases of compact as well as non-compact Cauchy surfaces are covered. The method employed uses a…

Analysis of PDEs · Mathematics 2015-08-07 Marcelo M. Disconzi

In this paper, the approach for investigation of asymptotic ($Re\to \infty$) scaling exponents of Eulerian structure functions (J. Schumacher et al, New. J. of Physics {\bf 9}, 89 (2007)) is generalized to studies of Lagrangian structure…

Fluid Dynamics · Physics 2009-11-25 Victor Yakhot

We revisit the issue of the correct Lagrangian description of a perfect fluid (pressure versus minus energy density) in relation with modified gravity theories in which galactic luminous matter couples nonminimally to the Ricci scalar.…

Astrophysics of Galaxies · Physics 2010-04-23 Valerio Faraoni

A Lagrangian relativistic approach to the non--linear dynamics of cosmological perturbations of an irrotational collisionless fluid is considered. Solutions are given at second order in perturbation theory for the relevant fluid and…

Astrophysics · Physics 2015-06-24 S. Matarrese , O. Pantano , D. Saez