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Related papers: A Relativistic view on large scale N-body simulati…

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We describe the irrotational dust component of the universe in terms of a relativistic gradient expansion and transform the resulting synchronous metric to a Newtonian coordinate system. The two metrics are connected via a space-like…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-06 Cornelius Rampf , Gerasimos Rigopoulos

Motivated by the results presented in a companion paper, here we give a simple analytical expression for the matter n-point functions in the Zel'dovich approximation (ZA) both in real and in redshift space (including the angular case). We…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Svetlin Tassev

This is the first in a series of papers devoted to fully general-relativistic $N$-body simulations applied to late-time cosmology. The purpose of this paper is to present the combination of a numerical relativity scheme, discretization…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-29 David Daverio , Yves Dirian , Ermis Mitsou

We study the dynamics of small inhomogeneities in an expanding universe collapsing to form bound structures using full solutions of the Einstein-Vlasov (N-body) equations. We compare these to standard Newtonian N-body solutions using…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-28 William E. East , Radosław Wojtak , Frans Pretorius

Doppler lensing, a relativistic effect resulting from the peculiar velocities of galaxies along the line of sight, provides insight into the large-scale structure of the Universe. Relativistic simulations are essential for modeling Doppler…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-23 Mubtasim Fuad , Sonia Akter Ema , Md Rasel Hossen

The standard cosmological model is inherently relativistic, and yet a wide range of cosmological observations can be predicted accurately from essentially Newtonian theory. This is not the case on `ultra-large' distance scales, around the…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-03 Louis Coates , Julian Adamek , Philip Bull , Caroline Guandalin , Chris Clarkson

In the standard approach to studying cosmological structure formation, the overall expansion of the Universe is assumed to be homogeneous, with the gravitational effect of inhomogeneities encoded entirely in a Newtonian potential. A topic…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-20 William E. East , Radosław Wojtak , Tom Abel

Relativistic cosmological perturbation analyses can be made based on several different fundamental gauge conditions. In the pressureless limit the variables in certain gauge conditions show the correct Newtonian behaviors. We consider the…

Astrophysics · Physics 2007-05-23 J. Hwang , H. Noh

We describe a wide class of inhomogeneous relativistic solutions that are well approximated on cosmological scales by solutions of Newtonian gravity. Error estimates measuring the difference between the Newtonian and relativistic solutions…

General Relativity and Quantum Cosmology · Physics 2014-06-06 Todd A. Oliynyk

Cosmological $N$-body simulations are the standard tool to study the emergence of the observed large-scale structure of the Universe. Such simulations usually solve for the gravitational dynamics of matter within the Newtonian…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-24 Jacob Brandbyge , Cornelius Rampf , Thomas Tram , Florent Leclercq , Christian Fidler , Steen Hannestad

Some of the dark matter in the Universe is made up of massive neutrinos. Their impact on the formation of large scale structure can be used to determine their absolute mass scale from cosmology, but to this end accurate numerical…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-09 Julian Adamek , Ruth Durrer , Martin Kunz

Distance measurements are usually thought to probe the background metric of the universe, but in reality the presence of perturbations will lead to deviations from the result expected in an exactly homogeneous and isotropic universe. At…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-23 Julian Adamek , Enea Di Dio , Ruth Durrer , Martin Kunz

We present $N$-body simulations in which either all, or a fraction of, the cold dark matter decays non-relativistically to a relativistic, non-interacting dark radiation component. All effects from radiation and general relativity are…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-19 Jeppe Dakin , Steen Hannestad , Thomas Tram

Numerical simulations of self-gravitating systems are generally based on N-body codes, which solve the equations of motion of a large number of interacting particles. This approach suffers from poor statistical sampling in regions of low…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 Giovanni Manfredi , Jean-Louis Rouet , Bruce Miller , Yui Shiozawa

In order to keep pace with the increasing data quality of astronomical surveys the observed source redshift has to be modeled beyond the well-known Doppler contribution. In this letter I want to examine the gauge issue that is often glossed…

General Relativity and Quantum Cosmology · Physics 2018-02-01 Julian Adamek

Nonlinear approximation methods such as the Zeldovich approximation, and more recently the frozen flow and linear potential approximations, are sometimes used to simulate nonlinear gravitational instability in the expanding Universe. We…

Astrophysics · Physics 2009-10-22 D. Munshi , A. A. Starobinsky

Beginning with a relativistic action principle for the irrotational flow of collisionless matter, we compute higher order corrections to the Zel'dovich approximation by deriving a nonlinear Hamilton-Jacobi equation for the velocity…

Astrophysics · Physics 2015-06-24 D. S. Salopek , J. M. Stewart , K. M. Croudace

Cosmological N-body simulations are now being performed using Newtonian gravity on scales larger than the Hubble radius. It is well known that a uniformly expanding, homogeneous ball of dust in Newtonian gravity satisfies the same equations…

General Relativity and Quantum Cosmology · Physics 2012-04-02 Stephen R. Green , Robert M. Wald

Ultra-large scales close to the cosmological horizon will be probed by the upcoming observational campaigns. They hold the promise to constrain single-field inflation as well as general relativity, but in order to include them in the…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-11 Thomas Montandon , Oliver Hahn , Clément Stahl

We present a numerical weak-lensing analysis that is fully relativistic and non-perturbative for the scalar part of the gravitational potential and first-order in the vector part, frame dragging. Integrating the photon geodesics backwards…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-26 Francesca Lepori , Julian Adamek , Ruth Durrer , Chris Clarkson , Louis Coates