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Related papers: Collisionless Dynamics and the Cosmic Web

200 papers

Collapse of the rotating spheroid is approximated by a system of ordinary differential equations describing its dynamics. The gravitational potential is approximated by the one of the iniform Maclaurin spheroid. Developement of…

Astrophysics · Physics 2016-08-30 G. S. Bisnovatyi-Kogan

We examine "dynamical similarities" in the Lagrangian framework. These are symmetries of an intrinsically determined physical system under which observables remain unaffected, but the extraneous information is changed. We establish three…

General Relativity and Quantum Cosmology · Physics 2018-07-04 David Sloan

In these lecture notes, we describe the current state-of-the-art for numerical simulations of large-scale structure and galaxy formation. Numerical simulations play a central role in the preparation and the exploitation of large-scale…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-16 Romain Teyssier

We present a new formalism to study large-scale structure in the universe. The result is a hierarchy (which we call the "Helmholtz Hierarchy") of equations describing the phase space statistics of cold dark matter (CDM). The hierarchy…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-21 Svetlin Tassev

We investigate the formation of spherical cosmological structures following both dark matter and gas components. We focus on the dynamical aspect of the collapse assuming an adiabatic, $\gamma = 5/3$, fully ionized primordial plasma. We use…

Astrophysics · Physics 2009-10-30 Jean-Pierre CHIEZE , Romain Teyssier , Jean-Michel Alimi

The Zeldovich approximation is applied to study the accretion of hot and cold dark matter onto moving long strings. It is assumed that such defects carry a substantial amount of small-scale structure, thereby acting gravitationally as a…

Astrophysics · Physics 2009-12-30 V. Zanchin , J. A. S. Lima , R. Brandenberger

Approximations to the exact solutions for gravitational instability in the expanding Universe are extremely useful for understanding the evolution of large--scale structure. We report on a series of tests of Newtonian Lagrangian…

Astrophysics · Physics 2007-05-23 T. Buchert , A. L. Melott , A. G. Weiss

The aim of this set of lectures is a systematic presentation of a 1+3 covariant approach to studying the geometry, dynamics, and observational properties of relativistic cosmological models. In giving (i) the basic 1+3 covariant relations…

General Relativity and Quantum Cosmology · Physics 2008-11-26 George F R Ellis , Henk van Elst

In this study, we meticulously construct a 3-form Lagrangian designed to mimic the dynamics of both dust matter in the past and dark energy driving the acceleration in the present era. A dynamical systems approach is used to investigate the…

General Relativity and Quantum Cosmology · Physics 2025-01-28 Vitor da Fonseca , Bruno J. Barros , Tiago Barreiro , Nelson J. Nunes

We present a new fast and efficient approach to model structure formation with Augmented Lagrangian Perturbation Theory (ALPT). Our method is based on splitting the displacement field into a long and a short-range component. The long-range…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Francisco-Shu Kitaura , Steffen Heß

The non-linear evolution of one-dimensional perturbations in a three-dimensional expanding Universe is considered. A general Lagrangian scheme is derived, and compared to two previously introduced approximate models. These models are…

Disordered Systems and Neural Networks · Physics 2007-05-23 Erik Aurell , Duccio Fanelli

We report the results of the first study of the multi-stream environment of dark matter haloes in cosmological N-body simulations in the LCDM cosmology. The full dynamical state of dark matter can be described as a three-dimensional…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-22 Nesar S. Ramachandra , Sergei F. Shandarin

The cosmic large-scale structure of our Universe is comprised of baryons and cold dark matter (CDM). Yet it is customary to treat these two components as a combined single-matter fluid with vanishing pressure, which is justified only for…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-04 Cornelius Rampf , Cora Uhlemann , Oliver Hahn

The Press-Schechter theory of the cosmological mass function and its modifications allow to constraint cosmological scenarios of the structure formation. Recently a few new models have been suggested that explored the influence of…

Astrophysics · Physics 2015-06-24 Sergei F. Shandarin

Cosmic voids have emerged as powerful probes for cosmology, providing complementary information on the large-scale structure of the universe. We present the first application of a hydrodynamical framework to model the evolution of cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-23 Tommaso Moretti , Giovanni Verza , Noemi Frusciante , Francesco Pace

The statistical tools needed to obtain a mass function from realistic collapse time estimates are presented. Collapse dynamics has been dealt with in paper I of this series by means of the powerful Lagrangian perturbation theory and the…

Astrophysics · Physics 2015-06-24 Pierluigi Monaco

We explore the possibility that the density profiles of elliptical galaxies and cold dark matter (CDM) halos found in cosmological simulations can be understood in terms of the same physical process, collisionless gravitational collapse. To…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-27 Eli Visbal , Abraham Loeb , Lars Hernquist

Persistent tensions in the $\Lambda$CDM cosmological model underline the importance of tests of its basic assumptions. One such potential test arises from the fact that the surface of zero expansion around the collapsing object with…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-21 Jan J. Ostrowski , Ismael Delgado Gaspar

We present an analytical model for the non-spherical collapse of overdense regions out of a Gaussian random field of initial cosmological perturbations. The collapsing region is treated as an ellipsoid of constant density, acted upon by the…

Astrophysics · Physics 2009-10-22 Daniel J. Eisenstein , Abraham Loeb

We investigate the collapse of three inelastic particles in dimension $d \geq 2$. We obtain general results of convergence and asymptotics concerning the variables of the dynamical system describing a collapsing system of particles. We…

Mathematical Physics · Physics 2025-10-09 Théophile Dolmaire , Juan J. L. Velázquez
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