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Related papers: Unveiling $f(R)$ Gravity with Void-Galaxy Cross-Co…

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The observed accelerated cosmic expansion can be a signature of fourth\,-\,order gravity theories, where the acceleration of the Universe is a consequence of departures from Einstein General Relativity, rather than the sign of the existence…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Vincenzo F. Cardone , Stefano Camera , Antonaldo Diaferio

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…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-26 N. Chandrachani Devi , Aldo Rodríguez-Puebla , O. Valenzuela , Vladimir Avila-Reese , César Hernández-Aguayo , Baojiu Li

Modifications to General Relativity typically introduce a scalar degree of freedom. Experimental constraints require that the "fifth" force produced by this field must be screened in high density environments. An important consequence of…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-27 Amol Upadhye , Jason H. Steffen

We consider the evolution of perturbations to a flat FRW universe that arise from a ``stiff source,'' such as a self-ordering cosmic field that forms in a global symmetry-breaking phase transition and evolves via the Kibble mechanism.…

Astrophysics · Physics 2009-10-22 Andrew H. Jaffe

The recent measurement of the gravitational redshifts of galaxies in galaxy clusters by Wojtak et al. has opened a new observational window on dark matter and modified gravity. By stacking clusters this determination effectively used the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Rupert A. C. Croft

In dynamical system describing evolution of universe with the flat Friedmann-Robertson-Walker symmetry filled with barotropic dust matter and non-minimally coupled scalar field with a constant potential function an invariant manifold of the…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-08 Orest Hrycyna

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…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-24 Harry Desmond , Pedro G Ferreira , Guilhem Lavaux , Jens Jasche

We examine general physical parameterisations for viable gravitational models in the $f(R)$ framework. This is related to the mass of an additional scalar field, called the scalaron, that is introduced by the theories. Using a simple…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Shaun A. Thomas , Stephen A. Appleby , Jochen Weller

In this paper, we consider a gravitational action containing a combination of the Ricci scalar, $R$, and the topological Gauss--Bonnet term, $G$. Specifically, we study the cosmological features of a particular class of modified gravity…

General Relativity and Quantum Cosmology · Physics 2023-03-15 Francesco Bajardi , Rocco D'Agostino

We study cosmological constraints on metric f(R) gravity models that are designed to reproduce the LCDM expansion history with modifications to gravity described by a supplementary cosmological freedom, the Compton wavelength parameter B_0.…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Lucas Lombriser , Anze Slosar , Uros Seljak , Wayne Hu

$f(R)$ theories of modified gravity may be compatible with current observations if the deviations from general relativity are sufficiently well screened in dense environments. In recent work [arXiv:2310.19955] we have shown that…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-20 Bradley March , Clare Burrage , Aneesh P. Naik

There is growing interest in testing alternative gravity theories using the subtle gravitational redshifts in clusters of galaxies. However, current models all neglect a transverse Doppler redshift of similar magnitude, and some models are…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Hongsheng Zhao , John Peacock , Baojiu Li

We propose a new version of the scalar Weak Gravity Conjecture (WGC) which would apply to any scalar field coupled to quantum gravity. For a single scalar it is given by the differential constraint $V''\leq…

High Energy Physics - Theory · Physics 2019-10-02 Eduardo Gonzalo , Luis E. Ibáñez

We present the first computation of the gravity model testing parameter $E_G$ on realistic simulated modified gravity galaxy mocks. The analysis is conducted using two twin simulations presented in arXiv:1805.09824(1): one based on general…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-19 C. Viglione , P. Fosalba , I. Tutusaus , L. Blot , J. Carretero , P. Tallada , F. Castander

In this study, we present constraints on the parameters of three well-known $f(R)$ gravity models, viz. (i) Hu-Sawicki, (ii) Starobinsky, and (iii) ArcTanh by using a joint analysis of recent cosmological observations. We perform analytical…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-30 Darshan Kumar , Praveen Kumar Dhankar , Saibal Ray , Fengge Zhang

We explore the late time cosmological dynamics of the Universe within the framework of $f(Q,\mathcal{L}_{m})$ gravity by considering the specific form $f(Q, \mathcal{L}_m)=-Q+2\mathcal{L}_m+\gamma$. To describe the cosmic pressure…

General Relativity and Quantum Cosmology · Physics 2025-08-08 Amit Samaddar , S. Surendra Singh

Testing a subset of viable cosmological models beyond General Relativity (GR), with implications for cosmic acceleration and the Dark Energy associated with it, is within the reach of Rubin Observatory Legacy Survey of Space and Time (LSST)…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-16 Nesar Ramachandra , Georgios Valogiannis , Mustapha Ishak , Katrin Heitmann

We study the variation of the gravitational Newton's constant on cosmological scales in scalar-tensor theories of gravity. We focus on the simplest models of scalar-tensor theories with a coupling to the Ricci scalar of the form $F(\sigma)…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-15 Mario Ballardini , Fabio Finelli , Domenico Sapone

Extremely large surveys with future experiments like Euclid and the SKA will soon allow us to access perturbation modes close to the Hubble scale, with wavenumbers $k \sim \mathcal{H}$. If a modified gravity theory is responsible for cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-03 Tessa Baker , Philip Bull