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We propose a new method to linearise cosmological mass density fields using higher order Lagrangian perturbation theory (LPT). We demonstrate that a given density field can be expressed as the sum of a linear and a nonlinear component which…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 F. S. Kitaura , R. E. Angulo

We identify materially defined regions in unsteady two-dimensional flows that combine finite-time contraction with elevated accumulated intrinsic rotation along trajectories, which we term \emph{Lagrangian rotating contracting structures}…

Chaotic Dynamics · Physics 2026-04-29 F. J. Beron-Vera

We report the systematic detection of magnetic fields in massive (M > 5 M$_\odot$) late-type supergiants, using spectropolarimetric observations obtained with ESPaDOnS at the Canada-France-Hawaii Telescope. Our observations reveal…

Solar and Stellar Astrophysics · Physics 2015-05-19 Jason H. Grunhut , Gregg A. Wade , David A. Hanes , Evelyne Alecian

Magnetically uncharged, magnetic linear response of the vacuum filled with arbitrarily combined constant electric and magnetic fields to an imposed static electric charge is found within general nonlinear electrodynamics. When the electric…

High Energy Physics - Theory · Physics 2020-05-26 T. C. Adorno , D. M. Gitman , A. E. Shabad

Dynamical systems that exhibit diverse behaviors can rarely be completely understood using a single approach. However, by identifying coherent structures in their state spaces, i.e., regions of uniform and simpler behavior, we could hope to…

Dynamical Systems · Mathematics 2013-01-01 Marko Budišić , Igor Mezić

The aim of the present paper is to introduce and to discuss inconsistencies errors that may arise when Eulerian and Lagrangian models are coupled for the simulations of turbulent poly-dispersed two-phase flows. In these hydrid models, two…

Fluid Dynamics · Physics 2011-04-07 Sergio Chibbaro , Jean-Pierre Minier

A conformal gauge theory is used to describe and unify myriad electromechanical and magnetomechanical coupling effects observed in solid continua. Using a space-time pseudo-Riemannian metric in a finite-deformation setup and exploiting the…

Classical Physics · Physics 2023-07-19 Pranesh Roy , Sanjeev Kumar , Debasish Roy

In this work, the benefits of the phase fitting technique are embedded in high order discrete Lagrangian integrators. The proposed methodology creates integrators with zero phase lag in a test Lagrangian in a similar way used in phase…

Instrumentation and Methods for Astrophysics · Physics 2009-04-02 O. T. Kosmas , D. S. Vlachos

One of the ubiquitous features of real-life turbulent flows is the existence and persistence of coherent vortices. Here we show that such coherent vortices can be extracted as clusters of Lagrangian trajectories. We carry out the clustering…

Chaotic Dynamics · Physics 2016-07-06 Alireza Hadjighasem , Daniel Karrasch , Hiroshi Teramoto , George Haller

Transport and mixing properties of surface currents can be detected from altimetric data by both Eulerian and Lagrangian diagnostics. In contrast with Eulerian diagnostics, Lagrangian tools like the local Lyapunov exponents have the…

Chaotic Dynamics · Physics 2009-01-14 F. d'Ovidio , J. Isern-Fontanet , C. Lopez , E. Hernandez-Garcia , E. Garcia-Ladona

Work presented in this paper describes a general algorithm and its finite element implementation for performing concurrent multiple sub-domain simulations in linear structural dynamics. Using this approach one can solve problems in which…

Numerical Analysis · Mathematics 2013-12-25 Tejas Ruparel , Azim Eskandarian , James Lee

Galaxies are observed to host magnetic fields with a typical total strength of around 15microgauss. A coherent large-scale field constitutes up to a few microgauss of the total, while the rest is built from strong magnetic fluctuations over…

Astrophysics of Galaxies · Physics 2024-01-09 Maarit J. Korpi-Lagg , Mordecai-Mark Mac Low , Frederick A. Gent

Fluctuation dynamo action has been obtained for a flow previously used to model fluid turbulence, where the sensitivity of the magnetic field parameters to the kinetic energy spectrum can be explored. We apply quantitative morphology…

Astrophysics · Physics 2008-11-26 S. Louise Wilkin , Carlo F. Barenghi , Anvar Shukurov

The method of Lagrangians with covariant derivative (MLCD) is applied to a special type of Lagrangian density depending on scalar and vector fields as well as on their first covariant derivatives. The corresponding Euler-Lagrange's…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Sawa Manoff

The goal of this paper is to apply the method of Lagrangian descriptors to reveal the phase space mechanism by which a Caldera-type potential energy surface (PES) exhibits the dynamical matching phenomenon. Using this technique, we can…

Chaotic Dynamics · Physics 2020-11-30 M. Katsanikas , Víctor J. García-Garrido , S. Wiggins

We present results from two-dimensional numerical simulations of a supersonic turbulent flow in the plane of the galactic disk, incorporating shear, thresholded and discrete star formation (SF), self-gravity, rotation and magnetic fields. A…

Astrophysics · Physics 2009-10-28 T. Passot , E. Vazquez-Semadeni , A. Pouquet

We consider a broad class of systems of nonlinear integro-differential equations posed on the real line that arise as Euler-Lagrange equations to energies involving nonlinear nonlocal interactions. Although these equations are not readily…

Dynamical Systems · Mathematics 2018-09-24 Bente Bakker , Arnd Scheel

A properly calibrated longitudinal magnetograph is an instrument that measures circular polarization and gives an estimation of the magnetic flux density in each observed resolution element. This usually constitutes a lower bound of the…

Solar and Stellar Astrophysics · Physics 2015-05-27 A. Asensio Ramos , M. J. Martinez Gonzalez , R. Manso Sainz

The Lagrangian formalism is used to derive covariant equations that are suitable for use in continuously distributed matter in curved spacetime. Special attention is given to theoretical representation, in which the Lagrangian and its…

General Physics · Physics 2025-02-19 Sergey G. Fedosin

By one of the most fundamental principles in physics, a dynamical system will exhibit those motions which extremise an action functional. This leads to the formation of the Euler-Lagrange equations, which serve as a model of how the system…

Machine Learning · Computer Science 2025-03-11 Yana Lishkova , Paul Scherer , Steffen Ridderbusch , Mateja Jamnik , Pietro Liò , Sina Ober-Blöbaum , Christian Offen
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