Related papers: Testing $f(R)$ Gravity With Scale Dependent Cosmic…
In modified gravity theories that seek to explain cosmic acceleration, dwarf galaxies in low density environments can be subject to enhanced forces. The class of scalar-tensor theories, which includes f(R) gravity, predict such a force…
Intra-galaxy signals contain a wealth of information on fundamental physics, both the dark sector and the nature of gravity. While so far largely unexplored, such probes are set to rise dramatically in importance as upcoming surveys provide…
In this paper we present preliminary results from cosmological simulations of modified gravity in the dark matter sector. Our results show improvements over standard cold dark matter cosmology. The abundance of low-mass haloes in the…
We study the effects of mass and force resolution on the density profiles of galaxy-size Cold Dark Matter (CDM) halos in a flat, low-density cosmological model with vacuum energy. We show thatalthough increasing the mass and force…
We consider $f(R)$ modified gravity theory incorporating the chameleon mechanism to address galactic dynamics. By employing the metric formalism and utilizing a conformal transformation, we simplify the field equations and describe the…
Modified gravity models with screening in local environments appear in three different guises: chameleon, K-mouflage and Vainshtein mechanisms. We propose to look for differences between these classes of models by considering cosmological…
It has been shown that the presence of non-minimally coupled scalar fields giving rise to a fifth force can noticeably alter dynamics on galactic scales. Such a fifth force must be screened in the Solar System but if unscreened it can have…
In this paper, we consider a cosmological model in $ f(R, G) $ gravity in a flat space-time, where $ R $ is the Ricci scalar and $ G $ is the Gauss-Bonnet invariant. The function $ f(R, G) $ is taken as a linear combination of $ R $ and an…
We describe how a certain simple modification of general relativity, in which the local cosmological constant is allowed to depend on the space-time curvature, predicts the existence of halos of modified gravity surrounding…
We investigate the dependence of the galaxy-halo connection and galaxy density field in modified gravity models using the $N-$body simulations for $f(R)$ and nDGP models at $z=0$. Because of the screening mechanisms employed by these…
In a recent paper, Alimi & Koskas highlighted in $w$CDM models derived from general relativity (GR) (with Dark Energy Universe numerical simulation data), a cosmological invariance of the distribution of dark-matter (DM) halo shapes when…
f(R) gravity is one of the simplest viable modifications to General Relativity: it passes local astrophysical tests, predicts both the early-time cosmic inflation and the late-time cosmic acceleration, and also describes dark matter. In…
We analyse the two-point and marked correlation functions of haloes and galaxies in three variants of the chameleon $f(R)$ gravity model using N-body simulations, and compare to a fiducial $\Lambda$CDM model based on general relativity…
We study the mass, velocity dispersion, and anisotropy profiles of $\Lambda$CDM halos using a suite of N-body simulations of unprecedented numerical resolution (the {\it Aquarius Project}). Our analysis confirms a number of results claimed…
Galaxies in cosmic voids have been reported with properties related to a delayed evolution with respect to the Universe in general. These characteristics reflect the interaction of galaxies with the environment. However, it is not clear the…
We consider the cosmologies that arise in a subclass of f(R) gravity with f(R)=R+\mu ^{2n+2}/(-R)^{n} and -1<n<0 in the metric (as opposed to the Palatini) variational approach to deriving the gravitational field equations. The calculations…
This article is devoted to investigate the effects of $f(R)$ theory in the dynamics of a massless particle near the horizon of a static spherically symmetric (SSS) black hole. Deriving the equations of motion within $f(R)$ gravitational…
We investigate the evolution of cosmic structures within the framework of modified gravity, specifically focusing on theories described by the function $f(R, L_m)$, where $R$ is the Ricci scalar and $L_m$ is the matter Lagrangian. This…
We present a Markov chain Monte Carlo pipeline that can be used for robust and unbiased constraints of $f(R)$ gravity using galaxy cluster number counts. This pipeline makes use of a detailed modelling of the halo mass function in $f(R)$…
We compute the bulk motions of cosmic voids, using a $\Lambda$CDM numerical simulation considering the mean velocities of the dark matter inside the void itself and that of the haloes in the surrounding shell. We find coincident values of…