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The Lagrangian perturbation theory on Friedman-Lemaitre cosmologies investigated and solved up to the second order in earlier papers (Buchert 1992, Buchert \& Ehlers 1993) is evaluated up to the third order. On its basis a model for…

Astrophysics · Physics 2015-06-24 Thomas Buchert

In this first paper we present a Lagrangian framework for the description of structure formation in general relativity, restricting attention to irrotational dust matter. As an application we present a self-contained derivation of a…

General Relativity and Quantum Cosmology · Physics 2012-07-24 Thomas Buchert , Matthias Ostermann

We quantitatively compare a particle implementation of the adhesion approximation to fully non--linear, numerical nbody simulations. Our primary tool, cross--correlation of nbody simulations with the adhesion approximation, indicates good…

Astrophysics · Physics 2009-10-22 A. L. Melott , S. F. Shandarin , D. H. Weinberg

We present a new formulation of Lagrangian perturbation theory which allows accurate predictions of the real- and redshift-space correlation functions of the mass field and dark matter halos. Our formulation involves a non-perturbative…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Jordan Carlson , Beth Reid , Martin White

This paper focusses on the barely understood gap between the weakly nonlinear regime of structure formation and the onset of the virialized regime. While the former is accessed through perturbative calculations and the latter through…

Astrophysics · Physics 2007-05-23 Thomas Buchert

The gravitational instability of inhomogeneities in the expanding universe is studied by the relativistic second-order approximation. Using the tetrad formalism we consider irrotational dust universes and get equations very similar to those…

Astrophysics · Physics 2009-10-28 H. Russ , M. Morita , M. Kasai , G. Boerner

A new theory for determining the mass function of cosmic structures is presented. It relies on a realistic treatment of collapse dynamics. Gravitational collapse is analyzed in the Lagrangian perturbative framework. Lagrangian perturbations…

Astrophysics · Physics 2015-06-24 Pierluigi Monaco

We compare relativistic approximation methods, which describe gravitational instability in the expanding universe, in a spherically symmetric model. Linear perturbation theory, second-order perturbation theory, relativistic Zel'dovich…

Astrophysics · Physics 2014-10-13 Masaaki Morita , Kouji Nakamura , Masumi Kasai

We study the initial conditions for cosmological $N$-body simulations for precision cosmology. In general, Zel'dovich approximation has been applied for the initial conditions of $N$-body simulations for a long time. These initial…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Takayuki Tatekawa

We discuss the relation between the output of Newtonian N-body simulations on scales that approach or exceed the particle horizon to the description of General Relativity. At leading order, the Zeldovich approximation is correct on large…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-27 Cornelius Rampf , Gerasimos Rigopoulos , Wessel Valkenburg

We investigate the performance of Lagrangian perturbation theory up to the second order for two scenarios of cosmological large-scale structure formation, SCDM (standard cold dark matter) and BSI (broken scale invariance). The latter model…

Astrophysics · Physics 2015-06-24 Arno G. Weiss , Stefan Gottloeber , Thomas Buchert

We report on the performance of Lagrangian perturbation theory up to the second order for the standard cold dark matter (SCDM) and broken scale invariance (BSI) scenarios. We normalize both models to the COBE data, the BSI model serves as…

Astrophysics · Physics 2007-05-23 A. G. Weiss , S. Gottloeber , T. Buchert

We implement an adaptation of the COLA approach, a hybrid scheme that combines Lagrangian perturbation theory with an N-body approach, to model non-linear collapse in chameleon and symmetron modified gravity models. Gravitational screening…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-30 Georgios Valogiannis , Rachel Bean

Previous work in the literature has studied the Hamiltonian structure of an R-squared model of gravity with torsion in a closed Friedmann-Robertson-Walker universe. Within the framework of Dirac's theory, torsion is found to lead to a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Giampiero Esposito , Gabriele Gionti , Giuseppe Marmo , Cosimo Stornaiolo

We consider the growth of primordial dark matter halos seeded by three crossed initial sine waves of various amplitudes. Using a Lagrangian treatment of cosmological gravitational dynamics, we examine the convergence properties of a…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-18 Shohei Saga , Atsushi Taruya , Stéphane Colombi

We investigate the Lagrangian perturbation theory of a general dark energy models with a constant equation of state, \omega, and derive the fitting form of the fastest growing mode solutions up to the third order. These fitting forms are…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-16 Seokcheon Lee

We analyzed the performance of a perturbation theory for nonlinear cosmological dynamics, based on the Lagrangian description of hydrodynamics. In our previous paper, we solved hydrodynamic equations for a self-gravitating fluid with…

Astrophysics · Physics 2009-11-10 Takayuki Tatekawa

We formulate a perturbative approximation to gravitational instability, based on Lagrangian hydrodynamics in Newtonian cosmology. We take account of `pressure' effect of fluid, which is kinematically caused by velocity dispersion, to aim…

Astrophysics · Physics 2009-11-07 Masaaki Morita , Takayuki Tatekawa

We compare different nonlinear approximations to gravitational clustering in the weakly nonlinear regime, using as a comparative statistic the evolution of non-Gaussianity which can be characterised by a set of numbers $S_p$ describing…

Astrophysics · Physics 2009-10-22 Dipak Munshi , Varun Sahni , Alexei A. Starobinsky

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