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An exact analytical method for determining the Lagrangian velocity correlation and the diffusion coefficient for particles moving in a stochastic velocity field is derived. It applies to divergence-free 2-dimensional Gaussian stochastic…

Plasma Physics · Physics 2007-05-23 M. Vlad , F. Spineanu , J. H. Misguich , R. Balescu

We introduce a Lagrangian-space Effective Field Theory (LEFT) formalism for the study of cosmological large scale structures. Unlike the previous Eulerian-space construction, it is naturally formulated as an effective field theory of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Rafael A. Porto , Leonardo Senatore , Matias Zaldarriaga

Contraction theory for dynamical systems on Euclidean spaces is well-established. For contractive (resp. semi-contractive) systems, the distance (resp. semi-distance) between any two trajectories decreases exponentially fast. For partially…

Optimization and Control · Mathematics 2021-06-07 Pedro Cisneros-Velarde , Saber Jafarpour , Francesco Bullo

We obtain approximations for the CDM particle trajectories starting from Lagrangian Perturbation Theory. These estimates for the CDM trajectories result in approximations for the density in real and redshift space, as well as for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Svetlin Tassev , Matias Zaldarriaga

We present a novel method to search for structures of coherently aligned patterns in ultra-high energy cosmic-ray arrival directions simultaneously across the entire sky. This method can be used to obtain information on the Galactic…

Instrumentation and Methods for Astrophysics · Physics 2022-01-31 Marcus Wirtz , Teresa Bister , Martin Erdmann

Standard diffuse approximations of the Willmore flow often lead to intersecting phase boundaries that in many cases do not correspond to the intended sharp interface evolution. Here we introduce a new two-variable diffuse approximation that…

Analysis of PDEs · Mathematics 2019-11-01 Andreas Rätz , Matthias Röger

In this work we investigate the nonlinear and nonlocal relation between cosmological density and peculiar velocity fields. Our goal is to provide an algorithm for the recon- struction of the nonlinear velocity field from the fully nonlinear…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Francisco-Shu Kitaura , Raul E. Angulo , Yehuda Hoffman , Stefan Gottl"ober

A scalar field model for explaining the anomalous acceleration and light deflection at galactic and cluster scales, without further dark matter, is presented. It is formulated in a scale covariant scalar tensor theory of gravity in the…

Astrophysics of Galaxies · Physics 2020-05-20 Erhard Scholz

The bacteria metabolic process of open nonlinear dissipative system far from equilibrium point is modeled using classical methods of synergetics. The invariant measure and its convergence in the phase space of the system was obtained in…

Chaotic Dynamics · Physics 2025-04-16 V. Grytsay

As most mathematically justifiable Lagrangian coherent structure detection methods rely on spatial derivatives, their applicability to sparse trajectory data has been limited. For experimental fluid dynamicists and natural scientists…

Fluid Dynamics · Physics 2024-11-20 Nikolas O. Aksamit , Alex P. Encinas-Bartos , George Haller , David E. Rival

We derive a simple consistency relation from the running of the tensor-to-scalar ratio. This new relation is first order in the slow-roll approximation. While for single field models we can obtain what can be found by using other…

Astrophysics · Physics 2009-11-06 Jinn-Ouk Gong

The identification and visualization of Lagrangian structures in flows plays a crucial role in the study of dynamic systems and fluid dynamics. The Finite Time Lyapunov Exponent (FTLE) has been widely used for this purpose; however, it only…

Dynamical Systems · Mathematics 2024-01-18 Yun Chen Tsai , Shingyu Leung

Explicit analytical expressions for the drag and diffusion coefficients of a spherical particle attached to the interface between two immiscible fluids are constructed for the case of a small viscosity ratio between the fluid phases. The…

Soft Condensed Matter · Physics 2016-04-20 Aaron Dörr , Steffen Hardt

We consider systems characterized by the presence of a rapidly oscillating force. A general method is presented for the construction of the effective action governing the large-scale nonlinear dynamics of such systems order by order in…

Chaotic Dynamics · Physics 2026-05-29 Afshin Besharat , Alexander A. Penin

We investigate the divergences appearing in the two-particle irreducible vertex functions of many-fermion systems with attractive on-site interactions. By means of dynamical mean-field theory calculations, we determine the location of…

Strongly Correlated Electrons · Physics 2020-05-11 D. Springer , P. Chalupa , S. Ciuchi , G. Sangiovanni , A. Toschi

In this paper, we consider the convergence rate with respect to the Wasserstein distance in the invariance principle for sequential dynamical systems. We utilize and modify the techniques previously employed for stationary sequences to…

Dynamical Systems · Mathematics 2024-10-29 Zhenxin Liu , Zhe Wang

Motion trajectory recognition is important for characterizing the moving property of an object. The speed and accuracy of trajectory recognition rely on a compact and discriminative feature representation, and the situations of varying…

Computer Vision and Pattern Recognition · Computer Science 2016-04-18 Xingyu Wu , Xia Mao , Lijiang Chen , Yuli Xue , Angelo Compare

Anti-selfdual Lagrangians on a state space lift to path space provided one adds a suitable selfdual boundary Lagrangian. This process can be iterated by considering the path space as a new state space for the newly obtained anti-selfdual…

Analysis of PDEs · Mathematics 2007-05-23 Nassif Ghoussoub , Leo Tzou

We describe a method for analyzing the phase space structures of Hamiltonian systems. This method is based on a time-frequency decomposition of a trajectory using wavelets. The ridges of the time-frequency landscape of a trajectory, also…

Chaotic Dynamics · Physics 2009-11-07 C. Chandre , S. Wiggins , T. Uzer

We show how the symmetry of attractors of equivariant dynamical systems can be observed by equivariant projections of the phase space. Equivariant projections have long been used, but they can give misleading results if used improperly and…

chao-dyn · Physics 2009-10-30 Jeffrey H. Schenker , James W. Swift