English
Related papers

Related papers: Emulation of $f(R)$ modified gravity from $\Lambda…

200 papers

We test the convergence of fast simulations based on the COmoving Lagrangian Acceleration (COLA) method for predictions of the matter power spectrum, specialising our analysis in the redshift range $1 \le z \le 1.65$, relevant to…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-21 Bartolomeo Fiorini , Kazuya Koyama , Tessa Baker

We study exact cosmological solutions in $f(Q)$ gravity formulated beyond the coincident gauge, focusing on the non-coincident connection branch $\Gamma_B$. Using a minisuperspace approach, the field equations are recast into an equivalent…

General Relativity and Quantum Cosmology · Physics 2025-09-18 Avik De , Andronikos Paliathanasis

The clustering ratio $\eta$, a large-scale structure observable originally designed to constrain the shape of the power spectrum of matter density fluctuations, is shown to provide a sensitive probe of the nature of gravity in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Julien Bel , Philippe Brax , Christian Marinoni , Patrick Valageas

We compare void size and clustering statistics for nDGP and $f(R)$ gravity models and GR using N-body simulations. We show how it is critical to consider the statistics derived from mock galaxy catalogs rather than the dark matter halos…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-21 Christopher Wilson , Rachel Bean

We put forward the idea that all the theoretically consistent models of gravity have contributions to the observed gravity interaction. In this formulation, each model comes with its own Euclidean path-integral weight where general…

General Relativity and Quantum Cosmology · Physics 2017-01-24 Nima Khosravi

The onset of dark energy domination depends on the particular gravitational theory driving the cosmic evolution. Model independent techniques are crucial to test both the present $\Lambda$CDM cosmological paradigm and alternative theories,…

General Relativity and Quantum Cosmology · Physics 2017-01-04 Álvaro de la Cruz-Dombriz , Peter K. S. Dunsby , Orlando Luongo , Lorenzo Reverberi

Near field cosmology is practiced by studying the Local Group (LG) and its neighbourhood. The present paper describes a framework for simulating the near field on the computer. Assuming the LCDM model as a prior and applying the Bayesian…

Models that seek to explain cosmic acceleration through modifications to General Relativity (GR) evade stringent Solar System constraints through a restoring, screening mechanism. Down-weighting the high density, screened regions in favor…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-30 Georgios Valogiannis , Rachel Bean

We apply and test a field-level emulator for non-linear cosmic structure formation in a volume matching next-generation surveys. Inferring the cosmological parameters and initial conditions from which the particular galaxy distribution of…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-20 Matthew T. Scoggins , Matthew Ho , Francisco Villaescusa-Navarro , Drew Jamieson , Ludvig Doeser , Greg L. Bryan

We investigate the linear cosmological perturbations in the context of the so-called energy-momentum squared gravity (EMSG) theory. Recent researches show that the EMSG theory can reproduce viable background cosmological evolution…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-17 Qi-Ming Fu , Xin Zhang

Over the last decade, much attention has been given to the study of modified gravity theories to find a more natural explanation for the late-time acceleration of the Universe. Particular attention has focused on the so-called $f(R)$ dark…

General Relativity and Quantum Cosmology · Physics 2024-08-09 Kelly MacDevette , Jess Worsley , Peter Dunsby , Saikat Chakraborty

Some aspects of two General Relativistic cosmological solutions, an exact $\Lambda$CDM-like cosmological solution $j=1$ ($j$ is cosmographic jerk parameter), and a specifically designed toy cosmological solution $j=1+3\varepsilon(q-1/2)$…

General Relativity and Quantum Cosmology · Physics 2026-02-09 Saikat Chakraborty , Piyabut Burikham

In this work we present a brief discussion about modified and extended cosmological models using current observational tests. We show that according to these astrophysical samples based in late universe measurements, theories like $f(R)$…

General Relativity and Quantum Cosmology · Physics 2021-01-25 Celia Escamilla-Rivera

The validation, verification, and uncertainty quantification of computationally expensive theoretical models of quantum many-body systems require the construction of fast and accurate emulators. In this work, we develop emulators for…

Machine Learning surrogates for Computational Fluid Dynamics (CFD), particularly Graph Neural Networks (GNNs) and Transformers, have become a new important approach for accelerating physics simulations. However, we identify a critical…

Machine Learning · Computer Science 2026-05-05 Paul Garnier , Vincent Lannelongue , Elie Hachem

We use properties of void populations identified in $N$-body simulations to forecast the ability of upcoming galaxy surveys to differentiate models of f(R) gravity from \lcdm~cosmology. We analyze multiple simulation realizations, which…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-24 Paul Zivick , P. M. Sutter , Benjamin D. Wandelt , Baojiu Li , Tsz Yan Lam

There has been a lot of research interest in modified gravity theories which utilise the Vainshtein mechanism to recover standard general relativity in regions with high matter density, such as the Dvali-Gabadadze-Porrati and Galileon…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-24 Baojiu Li , Gong-Bo Zhao , Kazuya Koyama

The accelerated expansion of the Universe remains one of the central open problems in modern cosmology. While the $\Lambda$CDM model successfully describes a wide range of observations, the physical nature of dark energy is still unknown,…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-08 Leandro Pardo , Leonardo Castañeda

Standard cosmological models rely on an approximate treatment of gravity, utilizing solutions of the linearized Einstein equations as well as physical approximations. In an era of precision cosmology, we should ask: are these approximate…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-06 John T. Giblin , James B. Mertens , Glenn D. Starkman , Chi Tian

One of the main science goals of the Large Synoptic Survey Telescope (LSST) is to uncover the nature of cosmic acceleration. In the base analysis, possible deviations from the Lambda-Cold-Dark-Matter ($\Lambda$CDM) background evolution will…