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Related papers: Solar-System Constraints on f(R) Chameleon Gravity

200 papers

We present a novel scenario where a scalar field acquires a mass which depends on the local matter density: the field is massive on Earth, where the density is high, but is essentially free in the solar system, where the density is low. All…

Astrophysics · Physics 2009-11-10 Justin Khoury , Amanda Weltman

Theories of gravity that incorporate new scalar degrees of freedom typically require screening mechanisms to ensure consistency with Solar System tests. One widely-studied mechanism -- the chameleon -- can lead to violations of the…

Astrophysics of Galaxies · Physics 2020-11-24 A. P. Naik , N. W. Evans , E. Puchwein , H. Zhao , A. -C. Davis

Scalar modifications of gravity have an impact on the growth of structure. Baryon and Cold Dark Matter (CDM) perturbations grow anomalously for scales within the Compton wavelength of the scalar field. In the late time Universe when…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Philippe Brax , Sébastien Clesse , Anne-Christine Davis

Models of modified gravity, whereby local tests of gravity are evaded thanks to a screening mechanism of the chameleon or Damour-Polyakov types, lead to a spatial variation of the particle masses and the fine structure constant. This is…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-09 Philippe Brax

We present a systematic comparison of several existing and new void finding algorithms, focusing on their potential power to test a particular class of modified gravity models - chameleon $f(R)$ gravity. These models deviate from standard…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-14 Marius Cautun , Enrique Paillas , Yan-Chuan Cai , Sownak Bose , Joaquin Armijo , Baojiu Li , Nelson Padilla

We use the recently released cosmic chronometer data and the latest measured value of the local Hubble parameter, combined with the latest joint light curves of Supernovae Type Ia, and Baryon Acoustic Oscillation distance measurements, in…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-09 Rafael C. Nunes , Supriya Pan , Emmanuel N. Saridakis , Everton M. C. Abreu

The gravitational dipole theory of Hadjukovic (2010) is based on the hypothesis that antimatter has a negative gravitational mass and thus falls upwards on Earth. Astrophysically, the model is similar to but more fundamental than Modified…

Earth and Planetary Astrophysics · Physics 2020-06-12 Indranil Banik , Pavel Kroupa

We investigate the Hubble constant tension within $f(R)$ modified gravity in the Jordan frame, focusing on its application to the dynamics of an isotropic Universe. A scalar field, non-minimally coupled to the metric, provides an extra…

General Relativity and Quantum Cosmology · Physics 2024-11-07 Tiziano Schiavone , Giovanni Montani

This article is dedicated to the use the MICROSCOPE mission's data to test chameleon theory of gravity. We take advantage of the technical sessions aimed to characterize the electrostatic stiffness of MICROSCOPE's instrument intrinsic to…

General Relativity and Quantum Cosmology · Physics 2021-03-31 Martin Pernot-Borràs , Joël Bergé , Philippe Brax , Jean-Philippe Uzan , Gilles Métris , Manuel Rodrigues , Pierre Touboul

Recently, a covariant spherically symmetric model of a black hole within the framework of loop quantum gravity (LQG), characterized by a quantum parameter $r_0$ or $\lambda$, has been proposed. To derive constraints on the LQG-corrected…

General Relativity and Quantum Cosmology · Physics 2024-01-10 Ruo-Ting Chen , Shulan Li , Li-Gang Zhu , Jian-Pin Wu

This paper is concerned with theories of gravity that contain a scalar coupled both conformally and disformally to matter through the metric. By systematically deriving the non-relativistic limit, it is shown that no new non-linear…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-10 Jeremy Sakstein

We discuss the scalar mode of gravitational waves emerging in the context of $F(R)$ gravity by taking into account the chameleon mechanism. Assuming a toy model with a specific matter distribution to reproduce the environment of detection…

General Relativity and Quantum Cosmology · Physics 2019-10-03 Taishi Katsuragawa , Tomohiro Nakamura , Taishi Ikeda , Salvatore Capozziello

Modified $f(R)$ gravity in the Palatini approach has been presently applied to Cosmology as a realistic alternative to dark energy. In this concern, a number of authors have searched for observational constraints on several $f(R)$ gravity…

Astrophysics · Physics 2009-06-23 F. C. Carvalho , E. M. Santos , J. S. Alcaniz , J. Santos

In this paper we study scalar perturbations of the metric for nonlinear $f(R)$ models. We consider the Universe at the late stage of its evolution and deep inside the cell of uniformity. We investigate the astrophysical approach in the case…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-04 Maxim Eingorn , Jan Novák , Alexander Zhuk

We investigate the impact of chameleon-type f(R) gravity models on the properties of galaxy clusters and groups. Our f(R) simulations follow for the first time also the hydrodynamics of the intracluster and intragroup medium. This allows us…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Christian Arnold , Ewald Puchwein , Volker Springel

The orbital Lense-Thirring precession is considered in the context of constraints for weak-field General Relativity involving the cosmological constant $\Lambda$. It is shown that according to the current accuracy of satellite measurements…

General Relativity and Quantum Cosmology · Physics 2020-10-06 A. Stepanian , Sh. Khlghatyan

We show that there is a fundamental flaw in the application of modified gravity theories in cosmology, taking $f(R)$ gravity as a paradigmatic example. This theory contains a scalar degree of freedom that couples to the matter stress-energy…

General Relativity and Quantum Cosmology · Physics 2024-04-09 Pablo A. Cano

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…

General Relativity and Quantum Cosmology · Physics 2024-07-22 J. K. Singh , Shaily , Anirudh Pradhan , Aroonkumar Beesham

Numerical simulations in modified gravity have commonly been performed under the quasi-static approximation -- that is, by neglecting the effect of time derivatives in the equation of motion of the scalar field that governs the fifth force…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-26 Sownak Bose , Wojciech A. Hellwing , Baojiu Li

In the framework of $f(T)$ theories of gravity, we solve the field equations for $f(T)=T+\alpha T^{n}$, in the weak-field approximation and for spherical symmetry spacetime. Since $f(T)=T$ corresponds to Teleparallel Gravity, which is…

General Relativity and Quantum Cosmology · Physics 2015-08-13 Lorenzo Iorio , Ninfa Radicella , Matteo Luca Ruggiero