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Related papers: $N$-body simulations for parametrised modified gra…

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In this paper we introduce a new public Einstein-Boltzmann solver, \texttt{MGCLASS II}, built as a modification to the publicly available \texttt{CLASS} code, that allows to obtain cosmological observables for Modified Gravity theories. It…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-28 Ziad Sakr , Matteo Martinelli

We consider modified gravity models driven by a scalar field whose effects are screened in high density regions due to the presence of non-linearities in its interaction potential and/or its coupling to matter. Our approach covers…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Philippe Brax , Anne-Christine Davis , Baojiu Li , Hans A. Winther

The testing of general relativity at cosmological scales has become a possible and timely endeavor that is not only motivated by the pressing question of cosmic acceleration but also by the proposals of some extensions to general relativity…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Jason Dossett , Mustapha Ishak , Jacob Moldenhauer

We present a field-level reaction framework to emulate the nonlinear effects of screened modified gravity on the cosmic web. This approach is designed to enable field-level inference with data from Stage IV cosmological surveys. Building on…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-22 Daniela Saadeh , Kazuya Koyama , Xan Morice-Atkinson

Model-independent tests of gravity with cosmology are important when testing extensions to the standard cosmological model. To maximise the impact of these tests one requires predictions for the matter power spectrum on non-linear scales.…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-18 Sankarshana Srinivasan , Daniel B Thomas , Richard Battye

We present a hydrodynamical description of spherical void evolution in modified gravity (MG), extending the standard General Relativity (GR) and dynamical dark energy treatment by encoding gravity modifications into effective couplings that…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-20 Tommaso Moretti , Noemi Frusciante , Giovanni Verza , Francesco Pace

The acceleration of the universe can be explained either through dark energy or through the modification of gravity on large scales. In this paper we investigate modified gravity models and compare their observable predictions with dark…

Astrophysics · Physics 2008-11-26 Edmund Bertschinger , Phillip Zukin

We present the first suite of cosmological N-body simulations that simultaneously include the effects of two different and theoretically independent extensions of the standard $\Lambda$CDM cosmological scenario - namely an $f(R)$ theory of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Marco Baldi , Francisco Villaescusa-Navarro , Matteo Viel , Ewald Puchwein , Volker Springel , Lauro Moscardini

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

We apply the technique of parameter-splitting to existing cosmological data sets, to check for a generic failure of dark energy models. Given a dark energy parameter, such as the energy density Omega_Lambda or equation of state w, we split…

Astrophysics · Physics 2008-11-26 Sheng Wang , Lam Hui , Morgan May , Zoltan Haiman

We introduce $k$-evolution, a relativistic $N$-body code based on $\textit{gevolution}$, which includes clustering dark energy among its cosmological components. To describe dark energy, we use the effective field theory approach. In…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-23 Farbod Hassani , Julian Adamek , Martin Kunz , Filippo Vernizzi

The evolution of an isolated over-density represents a useful toy model to test the accuracy of a cosmological N-body code in the non linear regime as it is approximately equivalent to that of a truly isolated cloud of particles, with same…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-07 Francesco Sylos Labini

We present a new high-resolution N-body algorithm for cosmological simulations. The algorithm employs a traditional particle-mesh technique on a cubic grid and successive multilevel relaxations on the finer meshes, introduced recursively in…

Astrophysics · Physics 2009-10-30 Andrey V. Kravtsov , Anatoly A. Klypin , Alexei M. Khokhlov

We present an algorithm for quickly generating multiple realizations of N-body simulations to be used, for example, for cosmological parameter estimation from surveys of large-scale structure. Our algorithm uses a new method to resample the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Michael D. Schneider , Shaun Cole , Carlos S. Frenk , Istvan Szapudi

The gravitationally-driven evolution of cold dark matter dominates the formation of structure in the Universe over a wide range of length scales. While the longest scales can be treated by perturbation theory, a fully quantitative…

Astrophysics · Physics 2009-11-10 Katrin Heitmann , Paul M. Ricker , Michael S. Warren , Salman Habib

The LCDM model is the most commonly admitted to describe our Universe. In spite of a great success with regard to the large scale structure formation, some problems are still unresolved at galactic scales. Alternative scenarios have to be…

Astrophysics · Physics 2007-09-24 O. Tiret , F. Combes

Within the effective field theory approach to cosmic acceleration, the background expansion can be specified separately from the gravitational modifications. We explore the impact of modified gravity in a background different from a…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Guilherme Brando , Felipe T. Falciano , Eric V. Linder , Hermano E. S. Velten

The increasing precision of cosmological data provides us with an opportunity to test general relativity (GR) on the largest accessible scales. Parameterizing modified gravity models facilitates the systematic testing of the predictions of…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-26 Ali Narimani , Douglas Scott

We review recent progress in the construction of modified gravity models as alternatives to dark energy as well as the development of cosmological tests of gravity. Einstein's theory of General Relativity (GR) has been tested accurately…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-24 Kazuya Koyama

Non-linear evolution of cosmological energy density fluctuations triggers deviations from Gaussianity in the temperature distribution of the cosmic microwave background. A method to estimate these deviations is proposed. N-body simulations…

Astrophysics · Physics 2009-11-07 A. M. Aliaga , V. Quilis , J. V. Arnau , D. Saez