English
Related papers

Related papers: From Manifolds to Lagrangian Coherent Structures i…

200 papers

We study the kinematics of stellar disc populations within the solar neighbourhood in order to find the imprints of the Galactic bar. We carry out the analysis by developing a numerical resolution of the 2D2V Collisionless Boltzmann…

Astrophysics of Galaxies · Physics 2018-05-16 Olivier Bienaymé

We develop a general theory of transport barriers for three-dimensional unsteady flows with arbitrary time-dependence. The barriers are obtained as two-dimensional Lagrangian Coherent Structures (LCSs) that create locally maximal…

Dynamical Systems · Mathematics 2015-06-16 Daniel Blazevski , George Haller

We study the dynamical interactions of mass systems in equilibrium under their own gravity that mutually exert and experience gravitational forces. The method we employ is to model the dynamical evolution of two isolated bars, hosted within…

Astrophysics of Galaxies · Physics 2017-07-12 F. Garzon , M. Lopez-Corredoira

The dynamic evolution of galactic bars in standard $\Lambda$CDM models is dominated by angular momentum loss to the dark matter haloes via dynamical friction. Traditional approximations to dynamical friction are formulated using the…

Astrophysics of Galaxies · Physics 2022-04-29 Rimpei Chiba , Ralph Schönrich

When bars form within galaxy formation simulations in the standard cosmological context, dynamical friction with dark matter (DM) causes them to rotate rather slowly. However, almost all observed galactic bars are fast in terms of the ratio…

Astrophysics of Galaxies · Physics 2021-03-30 Mahmood Roshan , Indranil Banik , Neda Ghafourian , Ingo Thies , Benoit Famaey , Elena Asencio , Pavel Kroupa

The central kpc of barred galaxies exhibits a wealth of morphological information on different components with clear dynamical consequences. These include nuclear rings, spirals, bars, and more. We argue that this morphology is driven by…

Astrophysics · Physics 2007-05-23 Isaac Shlosman

The detection of coherent structures is an important problem in fluid dynamics, particularly in geophysical applications. For instance, knowledge of how regions of fluid are isolated from each other allows prediction of the ultimate fate of…

Chaotic Dynamics · Physics 2013-05-28 Michael R. Allshouse , Jean-Luc Thiffeault

Many complex flows such as those arising from ocean plastics in geophysics or moving cells in biology are characterized by sparse and noisy trajectory datasets. We introduce techniques for identifying Lagrangian Coherent Structures (LCSs)…

Fluid Dynamics · Physics 2022-09-21 Saviz Mowlavi , Mattia Serra , Enrico Maiorino , L Mahadevan

In the present article, we present a new gravitational galactic model, describing motion in elliptical as well as in disk galaxies, by suitably choosing the dynamical parameters. Moreover, a new dynamical parameter, the S(g) spectrum, is…

Astrophysics of Galaxies · Physics 2012-04-03 Euaggelos E. Zotos

Recent advances enable the simultaneous computation of both attracting and repelling families of Lagrangian Coherent Structures (LCS) at the same initial or final time of interest. Obtaining LCS positions at intermediate times, however, has…

Dynamical Systems · Mathematics 2019-01-29 Daniel Karrasch , Mohammad Farazmand , George Haller

Stellar bars are a common morphological feature of spiral galaxies. While it is known that they can form in isolation, or be induced tidally, few studies have explored the production of stellar bars in galaxy merging. We look to investigate…

Astrophysics of Galaxies · Physics 2020-09-16 Mitchell Cavanagh , Kenji Bekki

The dynamics of supercooled liquid and glassy systems are usually studied within the Lagrangian representation, in which the positions and velocities of distinguishable interacting particles are followed. Within this representation,…

Disordered Systems and Neural Networks · Physics 2009-09-28 Claudio Chamon , Leticia F. Cugliandolo , Gabriel Fabricius , Jose Luis Iguain , Eric R. Weeks

This paper presents the formulations of nonlinear and linearized statics, dynamics, and control for any clustered tensegrity system (CTS). Based on the Lagrangian method and FEM assumptions, the nonlinear clustered tensegrity dynamics with…

Systems and Control · Electrical Eng. & Systems 2021-10-20 Shuo Ma , Muhao Chen , Robert E. Skelton

Galaxy morphology has many structures that are suggestive of various processes or stages of secular evolution. Internal perturbations such as bars can drive secular evolution through gravity torques that move gas into the central regions…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-15 Ronald J. Buta

We propose a theory to explain the formation of both spirals and rings in barred galaxies using a common dynamical framework. It is based on the orbital motion driven by the unstable equilibrium points of the rotating bar potential. Thus,…

Astrophysics · Physics 2016-11-23 M. Romero-Gomez

In this and in a previous paper (Romero-Gomez et al. 2006) we propose a theory to explain the formation of both spirals and rings in barred galaxies using a common dynamical framework. It is based on the orbital motion driven by the…

Astrophysics · Physics 2009-11-13 M. Romero-Gomez , E. Athanassoula , J. J. Masdemont , C. Garcia-Gomez

A concise method for following the evolving geometry of a moving surface using Lagrangian coordinates is described. All computations can be done in the fixed geometry of the initial surface despite the evolving complexity of the moving…

Soft Condensed Matter · Physics 2013-05-29 Mark A. Peterson

Recent observational constraints restrict the strict applicability of stellar dynamics in spirals to a few rotation periods. However, stellar dynamics concepts such as periodic orbits are invaluable for understanding the various dynamical…

Astrophysics · Physics 2008-02-03 D. Pfenniger

This chapter reviews theoretical work on the stellar dynamics of galaxy disks. All the known collective global instabilities are identified, and their mechanisms described in terms of local wave mechanics. A detailed discussion of warps and…

Astrophysics of Galaxies · Physics 2015-05-19 J. A. Sellwood

We examine the observable properties of simulated barred galaxies including radial mass profiles, edge-on structure and kinematics, bar lengths and pattern speed evolution for detailed comparison to real systems. We have run several…

Astrophysics · Physics 2009-11-07 J. K. O'Neill , J. Dubinski