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We present a new model based on General Relativity in where a subtle change of curvature at late times is able to produce the observed Universe acceleration and an oscillating behavior in the effective equation of state. This model aims to…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-18 A. Esteban-Gutiérrez , Miguel A. García-Aspeitia , A. Hernández-Almada , Juan Magaña , V. Motta

We show how to fully map a specific model of modified gravity into the Einstein-Boltzmann solver EFTCAMB. This approach consists in few steps and allows to obtain the cosmological phenomenology of a model with minimal effort. We discuss all…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-20 Bin Hu , Marco Raveri , Matteo Rizzato , Alessandra Silvestri

A class of well-behaved modified gravity models with long enough matter domination epoch and a late-time accelerated expansion is confronted with SNIa, CMB, SDSS, BAO and H(z) galaxy ages data, as well as current measurements of the linear…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-09 Z. Girones , A. Marchetti , O. Mena , C. Pena-Garay , N. Rius

We present new fitting functions for the velocity divergence auto- and cross-power spectra, $P_{\theta\theta}(k)$ and $P_{\delta\theta}(k)$, calibrated on gravity-only $N$-body simulations. By applying the Evolution Mapping framework, we…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-15 Matteo Esposito , Ariel G. Sánchez , Julien Bel , Andrés N. Ruiz

We investigate the impact on cosmological observables of $f(Q)$-gravity, a specific class of modified gravity models in which gravity is described by the non-metricity scalar, $Q$. In particular we focus on a specific model which is…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-24 Noemi Frusciante

We study the cosmology of a specific class of nonlocal model of modified gravity, the so-called Deser-Woodard (DW) model, modifying the Einstein-Hilbert action by a term $\sim R f(\Box^{-1}R)$, where $f$ is a free function. Choosing $f$ so…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-18 Luca Amendola , Yves Dirian , Henrik Nersisyan , Sohyun Park

The late stages of large-scale structure evolution are treated semi-analytically within the framework of modified halo model. We suggest simple yet accurate approximation for relating the non-linear amplitude to linear one for spherical…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-10 Yurij Kulinich , Bohdan Novosyadlyj , Stepan Apunevych

There has been recent interest in the cosmological consequences of energy-momentum-powered gravity models, in which the matter side of Einstein's equations is modified by the addition of a term proportional to some power, $n$, of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-29 M. C. F. Faria , C. J. A. P. Martins , F. Chiti , B. S. A. Silva

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 focus on weak inhomogeneous models of the Universe at low redshifts, described by the Lema\^itre-Tolman-Bondi (LTB) metric. The principal aim of this work is to compare the evolution of inhomogeneous perturbations in the $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-20 Tiziano Schiavone , Giovanni Montani

We study cosmological evolution in a flat FLRW spacetime in the context of modified STEGR gravity or $f(Q)$, using an exponential two-parameter model which represents a smooth perturbative expansion around the $\Lambda$CDM model. The…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Ivan R. Vasquez , A. Oliveros

$ $Future surveys could obtain tighter constraints on the cosmological parameters with the galaxy power spectrum than with the Cosmic Microwave Background. However, the inclusion of multiple overlapping tracers, redshift bins, and more…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-24 Yan Lai , Cullan Howlett , Tamara M. Davis

Model-independent parametrisations of modified gravity have attracted a lot of attention over the past few years and numerous combinations of experiments and observables have been suggested to constrain the parameters used in these models.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Daniel B. Thomas , Carlo R. Contaldi

We present MG-GLAM, a code developed for the very fast production of full $N$-body cosmological simulations in modified gravity (MG) models. We describe the implementation, numerical tests and first results of a large suite of cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-13 Cheng-Zong Ruan , César Hernández-Aguayo , Baojiu Li , Christian Arnold , Carlton M. Baugh , Anatoly Klypin , Francisco Prada

We explore the viable $f(R)$ gravity models in FLRW backgrounds with a free spatial curvature parameter $\Omega_{K}$. In our numerical calculation, we concentrate on the exponential $f(R)$ model of $f(R) = R - \lambda…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-18 Chao-Qiang Geng , Yan-Ting Hsu , Jhih-Rong Lu

We describe in detail the general methodology and numerical implementation of consistent N-body simulations for coupled scalar field cosmological models, including the background cosmology and the generation of initial conditions (with the…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-04 Baojiu Li , John D. Barrow

We propose a new framework for studying the cosmology of $f(R)$ gravity which completely avoids using the reconstruction programme. This allows us to easily obtain a qualitative feel of how much the $\Lambda$CDM model differs from other…

General Relativity and Quantum Cosmology · Physics 2021-06-22 Saikat Chakraborty , Kelly MacDevette , Peter Dunsby

Theoretical uncertainties on non-linear scales are among the main obstacles to exploit the sensitivity of forthcoming galaxy and hydrogen surveys like Euclid or the Square Kilometre Array (SKA). Here, we devise a new method to model the…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-06 Tim Sprenger , Maria Archidiacono , Thejs Brinckmann , Sébastien Clesse , Julien Lesgourgues

While the $\Lambda$CDM model succeeds on large scales, its validity on smaller scales remains uncertain. Recent works suggest that non-halo dark matter structures, such as filaments and walls, could significantly influence gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-21 Baptiste Jego , Giulia Despali , Tamara Richardson , Jens Stücker

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
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