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To fully take advantage of the data provided by large-scale structure surveys, we need to quantify the potential impact of baryonic effects, such as feedback from active galactic nuclei (AGN) and star formation, on cosmological observables.…

Cosmological simulations require the use of a multiple time-stepping scheme. Without such a scheme, cosmological simulations would be impossible due to their high level of dynamic range; over eleven orders of magnitude in density. Such a…

Distributed, Parallel, and Cluster Computing · Computer Science 2018-07-05 Josh Borrow , Richard G. Bower , Peter W. Draper , Pedro Gonnet , Matthieu Schaller

A range of cosmological observations demonstrate an accelerated expansion of the Universe, and the most likely explanation of this phenomenon is a cosmological constant. Given the importance of understanding the underlying physics, it is…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-07 Karoline Loeve , Kristine Simone Nielsen , Steen H. Hansen

We identify a scalar-tensor model embedded in the Horndeski action whose cosmological background and linear scalar fluctuations are degenerate with the concordance cosmology. The model admits a self-accelerated background expansion at late…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-17 Lucas Lombriser , Andy Taylor

Cosmological simulations involving the fully covariant gravitational dynamics may prove relevant in understanding relativistic/non-linear features and, therefore, in taking better advantage of the upcoming large scale structure survey data.…

General Relativity and Quantum Cosmology · Physics 2017-11-15 David Daverio , Yves Dirian , Ermis Mitsou

The development of numerical N -body simulations have allowed to study formation process and evolution of galaxies at different scales. This paper presents the fundamental concepts of N-body systems applied to the cosmological evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-12 Jazhiel Chacon , J. Alberto Vazquez , Ruslan Gabbasov

According to the separate universe conjecture, spherically symmetric sub-regions in an isotropic universe behave like mini-universes with their own cosmological parameters. This is an excellent approximation in both Newtonian and general…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-14 Gábor Rácz , László Dobos , Róbert Beck , István Szapudi , István Csabai

Cosmological N-body simulations aim to calculate the non-linear gravitational growth of structures via particle dynamics. A crucial problem concerns the setting-up of the initial particle distribution, as standard theories of galaxy…

Astrophysics · Physics 2010-12-09 Thierry Baertschiger , Francesco Sylos Labini

Adaptive techniques are crucial for successful numerical modeling of gravitational waves from astrophysical sources such as coalescing compact binaries, since the radiation typically has wavelengths much larger than the scale of the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Kimberly C. B. New , Dae-Il Choi , Joan M. Centrella , Peter MacNeice , Mijan F. Huq , Kevin Olson

We investigate the information on cosmology contained in Gaussianised weak gravitational lensing convergence fields. Employing Box-Cox transformations to determine optimal transformations to Gaussianity, we develop analytical models for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 B. Joachimi , A. N. Taylor , A. Kiessling

We introduce the Cluster-EAGLE (C-EAGLE) simulation project, a set of cosmological hydrodynamical zoom simulations of the formation of $30$ galaxy clusters in the mass range $10^{14}<M_{200}/\mathrm{M}_{\odot}<10^{15.4}$ that incorporates…

We introduce Project GIBLE (Gas Is Better resoLved around galaxiEs), a suite of cosmological zoom-in simulations where gas in the circumgalactic medium (CGM) is preferentially simulated at ultra-high numerical resolution. Our initial sample…

Astrophysics of Galaxies · Physics 2023-07-24 Rahul Ramesh , Dylan Nelson

It is commonly stated that we have entered the era of precision cosmology in which a number of important observations have reached a degree of precision, and a level of agreement with theory, that is comparable with many Earth-based physics…

General Physics · Physics 2011-10-31 Marie-Noëlle Célérier

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 present an end-to-end description of the formation process of globular clusters (GCs) which combines a treatment for their formation and dynamical evolution within galaxy haloes with a state-of-the-art semi-analytic simulation of galaxy…

In the context of f(R) theories of gravity, we study the cosmological evolution of scalar perturbations by using a completely general procedure. We find that the exact fourth-order differential equation for the matter density perturbations…

Astrophysics · Physics 2015-05-13 A. de la Cruz-Dombriz , A. Dobado , A. L. Maroto

We study the evolution of matter density perturbations in Galileon cosmology where the late-time cosmic acceleration can be realized by a field kinetic energy. We obtain full perturbation equations at linear order in the presence of five…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-23 Antonio De Felice , Ryotaro Kase , Shinji Tsujikawa

Many phenomenologically successful cosmological galaxy formation simulations employ kinetic winds to model galactic outflows, a crucial ingredient in obtaining predictions that agree with various observations. Yet systematic studies of how…

The 1+3 covariant approach and the covariant gauge-invariant approach to perturbations are used to analyze in depth conformal transformations in cosmology. Such techniques allow us to obtain very interesting insights on the physical content…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Sante Carloni , Emilio Elizalde , Sergei Odintsov

We introduce the Virgo Consortium's EAGLE project, a suite of hydrodynamical simulations that follow the formation of galaxies and black holes in representative volumes. We discuss the limitations of such simulations in light of their…