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We use low-redshift background cosmology data to place quantitative constraints on three separate modified gravity models, each of which aims to explain the low-redshift acceleration through a different physical mechanism. The Lifshitz…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 S. R. Pinto , A. M. Cabral , C. J. A. P. Martins

We present measurements of both scale- and time-dependent deviations from the standard gravitational field equations. These late-time modifications are introduced separately for relativistic and non-relativistic particles, by way of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-16 Andrew Johnson , Chris Blake , Jason Dossett , Jun Koda , David Parkinson , Shahab Joudaki

The cosmic acceleration problem remains one of the most significant challenges in cosmology. One of the proposed solutions to this problem is the modification of gravity on large scales. In this paper, we explore the well-known…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-04 Uendert Andrade , Abraão J. S. Capistrano , Eleonora Di Valentino , Rafael C. Nunes

A unified framework for theories of modified gravity will be an essential tool for interpreting the forthcoming deluge of cosmological data. We present such a formalism, the Parameterized Post-Friedmann framework (PPF), which parameterizes…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-08 Tessa Baker , Pedro G. Ferreira , Constantinos Skordis

Various experiments and observations have led researchers to suggest different bounds on fundamental constants like the fine-structure constant and the proton-to-electron mass ratio. These bounds differ mostly due to the energy scale of the…

General Relativity and Quantum Cosmology · Physics 2023-06-05 Surajit Kalita , Akhil Uniyal

We show that fundamental plane of elliptical galaxies can be used to obtain observational constraints on metric theories of gravity. Being it connected to global properties of ellipticals, it can fix parameters of modified gravity.…

General Relativity and Quantum Cosmology · Physics 2020-04-27 Salvatore Capozziello , Vesna Borka Jovanović , Duško Borka , Predrag Jovanović

In 'modified' gravity the observed acceleration of the universe is explained by changing the gravitational force law or the number of degrees of freedom in the gravitational sector. Both possibilities can be tested by measurements of…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Clare Burrage , David Parkinson , David Seery

We impose the first strong-lensing constraints on a wide class of modified gravity models where an extra field that modifies gravity also couples to photons (either directly or indirectly through a coupling with baryons) and thus modifies…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-09 De-Chang Dai , Dejan Stojkovic , Glenn D. Starkman

A new approach is proposed to phenomenological study of a generic unified supergravity model, which reduces to the minimal supersymmetric standard model. The model is effectively parametrized in terms of five low energy observables. In…

High Energy Physics - Phenomenology · Physics 2009-10-22 M. Olechowski , S. Pokorski

Parameterized frameworks for modified gravity are potentially useful tools for model-independent tests of General Relativity on cosmological scales. The toy model of an Einstein-de Sitter (EdS) universe provides a safe testbed in which to…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Tessa Baker

In this work we present updated forecasts on parameterised modifications of gravity that can capture deviations of the behaviour of cosmological density perturbations beyond $\Lambda$CDM. For these forecasts we adopt the SKA Observatory…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-13 Santiago Casas , Isabella P. Carucci , Valeria Pettorino , Stefano Camera , Matteo Martinelli

We investigate cosmological constraints on K-mouflage models of modified gravity. We consider two scenarios: one where the background evolution is free to deviate from $\Lambda$CDM (K-mouflage) and another one which reproduces a…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-29 Giampaolo Benevento , Marco Raveri , Andrei Lazanu , Nicola Bartolo , Michele Liguori , Philippe Brax , Patrick Valageas

We explore the shifted $f(R) (\propto R^{1+\delta})$ model with ${\delta}$ as a distinguishing physical parameter for the study of constraints at local scales. The corresponding dynamics confronted with different geodesics (null and…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-05 Vipin Kumar Sharma , Murli Manohar Verma

Alternative theories of gravity may serve to overcame several shortcomings of the standard cosmological model but, in their weak field limit, General Relativity must be recovered so as to match the tight constraints at the Solar System…

General Relativity and Quantum Cosmology · Physics 2018-06-06 Mariafelicia De Laurentis , Ivan De Martino , Ruth Lazkoz

We perform observational tests of modified gravity on cosmological scales following model-dependent and model-independent approaches using the latest astronomical observations, including measurements of the local Hubble constant, cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-04 Jian Li , Gong-Bo Zhao

We use astrophysical data to shed light on fundamental physics by constraining parametrized theoretical cosmological and gravitational models. Gravitational parameters are those constants that parametrize possible departures from Einstein's…

Astrophysics · Physics 2008-08-18 Yi Mao

One way to account for the acceleration of the universe is to modify general relativity, rather than introducing dark energy. Typically, such modifications introduce new degrees of freedom. It is interesting to consider models with no new…

Astrophysics · Physics 2011-05-12 Sean M. Carroll , Ignacy Sawicki , Alessandra Silvestri , Mark Trodden

This study is devoted to the implications of scale-dependent gravity in Cosmology. Redshift-space distortion data indicate that there is a tension between $\Lambda$CDM and available observations as far as the value of the rms density…

General Relativity and Quantum Cosmology · Physics 2021-06-08 Grigoris Panotopoulos , Ángel Rincón

At linear order in cosmological perturbations, departures from the growth in the cosmological standard model can be quantified in terms of two functions of redshift $z$ and Fourier number $k$. Previous studies have performed principal…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Alireza Hojjati , Levon Pogosian , Alessandra Silvestri , Gong-Bo Zhao

We investigate the prospects for constraining alternative theories of gravity with a typical near-term low-budget 21 cm intensity mapping experiment. We derive the 21 cm brightness temperature perturbation consistently in linear theory…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-26 Alex Hall , Camille Bonvin , Anthony Challinor
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