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Related papers: Modified Gravity Away from a $\Lambda$CDM Backgrou…

200 papers

We provide an end-to-end exploration of a distinct modified gravitational theory in Jordan-Brans-Dicke (JBD) gravity, from an analytical and numerical description of the background expansion and linear perturbations, to the nonlinear regime…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-17 Shahab Joudaki , Pedro G. Ferreira , Nelson A. Lima , Hans A. Winther

We study observational constraints on the non-metricity $f(Q)$-gravity which reproduces an exact $\Lambda$CDM background expansion history while modifying the evolution of linear perturbations. To this purpose we use Cosmic Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-29 Luís Atayde , Noemi Frusciante

Gravitational interaction of cosmic microwave background (CMB) photons with matter perturbations present along the line-of-sight to the surface of last scattering modifies the shape of the CMB anisotropy power spectrum. Here I focus on…

Astrophysics · Physics 2011-07-28 Radek Stompor

The modified gravity with $\ln R$ or $R^{-n} (\ln R)^m$ terms which grow at small curvature is discussed. It is shown that such a model which has well-defined newtonian limit may eliminate the need for dark energy and may provide the…

High Energy Physics - Theory · Physics 2009-09-17 Shin'ichi Nojiri , Sergei D. Odintsov

The presently open problem of the Hubble tension is shown to be removed in the context of a modified theory of gravity with a non-minimal coupling between curvature and matter. By evolving the cosmological parameters that match the cosmic…

General Relativity and Quantum Cosmology · Physics 2024-10-22 Miguel Barroso Varela , Orfeu Bertolami

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…

Astrophysics · Physics 2008-07-08 Wojciech A. Hellwing

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

A Bayesian statistical analysis using redshift space distortions data is performed to test a model of Symmetric Teleparallel Gravity where gravity is non-metrical. The cosmological background mimics a $\Lambda$CDM evolution but differences…

General Relativity and Quantum Cosmology · Physics 2020-06-15 Bruno J. Barros , Tiago Barreiro , Tomi Koivisto , Nelson J. Nunes

We consider cosmological constraints arising from the background expansion history on the ef- fective field theory of cosmic acceleration, a theoretical framework that allows for a unified way to classify both models of dark energy and…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-10 Eva-Maria Mueller , Rachel Bean , Scott Watson

In models of modified gravity, extra degrees of freedom usually appear. They must be removed from the spectrum because they may indicate the presence of instabilities and because otherwise the model might not agree with observation. In the…

High Energy Physics - Theory · Physics 2014-11-18 Luca Grisa

We address the impact of consistent modifications of gravity on the largest observable scales, focusing on relativistic effects in galaxy number counts and the cross-correlation between the matter large scale structure (LSS) distribution…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-26 Janina Renk , Miguel Zumalacarregui , Francesco Montanari

The late time acceleration of the Universe has challenged contemporary cosmology since its discovery. General Relativity explains this phenomenon by introducing the cosmological constant, named the standard cosmological model…

General Relativity and Quantum Cosmology · Physics 2024-01-02 Simran Arora

We investigate the contributions of the Friedmann-Lema\^itre-Robertson-Walker metric of the standard cosmology as an asymptotic boundary condition on the first-order approximation of the gravitational field in Moffat's theory of modified…

General Relativity and Quantum Cosmology · Physics 2021-09-24 J. W. Moffat , V. T. Toth

General Relativity (GR) is consistent with a wide range of experiments/observations from millimeter scales up to galactic scales and beyond. However, there are reasons to believe that GR may need to be modified because it includes…

General Relativity and Quantum Cosmology · Physics 2019-07-17 Leandros Perivolaropoulos , Lavrentios Kazantzidis

A modification of the action of the general relativity produces a different pattern for the growth of the cosmic structures below a certain length-scale leaving an imprint on the cosmic microwave background (CMB) anisotropies. We re-examine…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-01 Andrea Marchini , Valentina Salvatelli

Nonlocal massive gravity can provide an interesting explanation for the late-time cosmic acceleration, with a dark energy equation of state $w_{\rm DE}$ smaller than $-1$ in the past. We derive the equations of linear cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-11 Savvas Nesseris , Shinji Tsujikawa

In modern cosmology, the curiosity of ultimately understanding the nature of the dark energy controlling the recent acceleration of the Universe motivates us to explore its properties by using some novel approaches. In this work, to explore…

General Relativity and Quantum Cosmology · Physics 2023-12-19 Sanjay Mandal , Sneha Pradhan , P. K. Sahoo , Tiberiu Harko

We explore the phenomenological consequences of general late-time modifications of gravity in the quasi-static approximation, in the case where cold dark matter is non-minimally coupled to the gravitational sector. Assuming spectroscopic…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-16 Jérôme Gleyzes , David Langlois , Michele Mancarella , Filippo Vernizzi

We analyse the implications of the presence of spatial curvature in modified gravity models. As it is well known, the current standard cosmological model, the $\Lambda$CDM, is assumed to be spatially flat based on the results of many…

General Relativity and Quantum Cosmology · Physics 2024-12-03 Serena Gambino , Francesco Pace

This review presents a comprehensive overview of Myrzakulov gravity, highlighting key developments and significant results shaping the theory. It examines the foundational principles, field equations, and the role of non-metricity and…

General Relativity and Quantum Cosmology · Physics 2025-04-04 Davood Momeni , Ratbay Myrzakulov