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We present an efficient numerical algorithm for evolving self-gravitating systems of dark-matter particles that leverages the assumption of spherical symmetry to reduce the nominally six-dimensional phase space to three dimensions. It can…

Astrophysics of Galaxies · Physics 2025-04-22 Marc Kamionkowski , Kris R. Sigurdson

Infinitesimal volumes stretch and contract as they coevolve with classical phase space trajectories according to linearized dynamics. Unless these tangent-space dynamics are modified, chaotic evolution causes the volume spanned by evolving…

Chaotic Dynamics · Physics 2026-04-13 Swetamber Das , Jason R. Green

Traditionally, the deformation of continuum is divided into elastic, plastic, and flow. For a large deformation with cracking, they are combined together. So, for complicated deformation, a formulation to express the evolution of…

Classical Physics · Physics 2007-05-23 Jianhua Xiao

We consider a one dimensional infinite acoustic chain of harmonic oscillators whose dynamics is perturbed by a random exchange of velocities, such that the energy and momentum of the chain are conserved. Consequently, the evolution of the…

Statistical Mechanics · Physics 2016-02-17 Tomasz Komorowski , Stefano Olla

As it collapses to form a halo, the shape of a protohalo patch is deformed by the initial shear field. This deformation is often modeled using the "deformation" tensor, constructed from second derivatives of the gravitational potential,…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-09 Marcello Musso , Giulia Despali , Ravi K. Sheth

We investigate numerically the yielding transition of a two dimensional model amorphous solid under external shear. We use a scalar model in terms of values of the total local strain, that we derive from the full (tensorial) description of…

Statistical Mechanics · Physics 2018-07-18 I. Fernández Aguirre , E. A. Jagla

Cold dark matter cosmogony predicts triaxial dark matter halos, whereas observations find quite round halos. This is most likely due to the condensation of baryons leading to rounder halos. We examine the halo phase space distribution basis…

The flow of thin liquid films on inclined or vertical surfaces is one of immense importance, with applications spanning many types of process industries, due to the increased mass and heat transfer brought about by the presence of waves on…

Soft Condensed Matter · Physics 2020-07-24 Idris Adebayo

The evolution of the two-point correlation function, xi(r,z), and the pairwise velocity dispersion, sigma(r,z), for both the matter and halo population, in three different cosmological models: (Omega_M,Omega_Lambda)=(1,0), (0.2,0) and…

Astrophysics · Physics 2009-10-28 P. Colin , R. G. Carlberg , H. M. P. Couchman

Self-consistent solutions for triaxial mass models are highly non-unique. In general, some of these solutions might be dynamically unstable, making them inappropriate as descriptions of steady-state galaxies. Here we demonstrate for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Fabio Antonini , Roberto Capuzzo-Dolcetta , David Merritt

Conformal field theories with central charge $c\le1$ on random surfaces have been extensively studied in the past. Here, this discussion is extended from their equilibrium distribution to their critical dynamics. This is motivated by the…

High Energy Physics - Theory · Physics 2025-06-03 Christof Schmidhuber

The halo shape plays a central role in determining important observational properties of the haloes such as mass, concentration and lensing cross-sections. The triaxiality of lensing galaxy clusters has a substantial impact on the…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Jesús Vega-Ferrero , Gustavo Yepes , Stefan Gottlöber

The temporal evolution of step-edge fluctuations under electromigration conditions is analysed using a continuum Langevin model. If the electromigration driving force acts in the step up/down direction, and step-edge diffusion is the…

Materials Science · Physics 2009-11-13 P. J. Rous , T. W. Bole

Many nonlinear partial differential equations (PDEs) display a coarsening dynamics, i.e., an emerging pattern whose typical length scale $L$ increases with time. The so-called coarsening exponent $n$ characterizes the time dependence of the…

Pattern Formation and Solitons · Physics 2013-06-11 Matteo Nicoli , Chaouqi Misbah , Paolo Politi

We investigate non-linear scaling relations for two-dimensional gravitational collapse in an expanding background using a 2D TreePM code and study the strongly non-linear regime ($\bar\xi \leq 200$) for power law models. Evolution of these…

Astrophysics · Physics 2007-05-23 S. Ray , J. S. Bagla , T. Padmanabhan

We analyze the physical justification of the picture proposed by Salvador-Sole et al. in these proceedings for the time evolution of the universal density profile of dark-matter halos. According to this picture, halos have at formation a…

Astrophysics · Physics 2007-05-23 G. Gonzalez-Casado , A. Raig , E. Salvador-Sole

The collapse of a rotating 3-axis ellipsoid is approximated by a system of ordinary differential equations. Violent relaxation, mass and angular momentum losses are taken into account phenomenologically. The formation of the equilibrium…

Astrophysics · Physics 2007-05-23 O. Yu. Tsupko , G. S. Bisnovatyi-Kogan

We present $N$--body models for triaxial elliptical galaxies or halos of galaxies, which are fully self--gravitating, have near constant axis ratio as a function of radius and a $r^{-1}$ central density cusp. Preliminary investigation…

Astrophysics · Physics 2007-05-23 Steinn Sigurdsson , Chris Mihos , Lars Hernquist , Colin Norman

A database on shape evolution of direct N-body models formed out of cold, dissipationless collapse is generated using GRAPE and HARP special purpose computers. Such models are important to understand the formation of elliptical galaxies.…

Astrophysics · Physics 2007-05-23 Ch. Theis , R. Spurzem

Holography has provided valuable insights into the time evolution of strongly coupled gauge theories in a fixed spacetime. However, this framework is insufficient if this spacetime is dynamical. We present a scheme to evolve a…

High Energy Physics - Theory · Physics 2022-03-30 Christian Ecker , Wilke van der Schee , David Mateos , Jorge Casalderrey-Solana