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Related papers: New probe of modified gravity

200 papers

We consider f(R,T) modified theory of gravity, in which the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar and the trace of the energy-momentum tensor of the matter, in order to investigate the dark-matter…

General Relativity and Quantum Cosmology · Physics 2016-11-02 Raziyeh Zaregonbadi , Mehrdad Farhoudi , Nematollah Riazi

We consider new models of dark energy with finite time future singularities, by introducing the pressure density as a function of the scale factor. This approach gives acceptable phenomenological models of dark energy, practically…

General Relativity and Quantum Cosmology · Physics 2019-07-17 L. N. Granda

We present a model that builds ``dark matter"-like halo density profiles from free-falling zero-point vacuum fluctuations. It does not require a modification of Newton's laws, nor the existence of as-yet-undiscovered dark matter particles.…

General Relativity and Quantum Cosmology · Physics 2023-02-06 François Couchot , Arache Djannati-Ataï , Scott Robertson , Xavier Sarazin , Marcel Urban

We implement an adaptation of the COLA approach, a hybrid scheme that combines Lagrangian perturbation theory with an N-body approach, to model non-linear collapse in chameleon and symmetron modified gravity models. Gravitational screening…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-30 Georgios Valogiannis , Rachel Bean

Theories of modified gravity attempt to reconcile physics at the largest and the smallest scales by explaining the accelerated expansion of our universe without introducing the cosmological constant. One class of such theories, known as…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-11 Youngsoo Park , Mark Wyman

In this paper, we analyze the clustering of galaxies using a modified theory of gravity, in which the field content of general relativity has been be increased. This increasing in the field content of general relativity changes the large…

General Relativity and Quantum Cosmology · Physics 2019-11-06 Mir Hameeda , Behnam Pourhassan , Mir Faizal , C. P. Masroor , Rizwan Ul Haq Ansari , P. K. Suresh

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

Modifications of general relativity provide an alternative explanation to dark energy for the observed acceleration of the universe. We review recent developments in modified gravity theories, focusing on higher dimensional approaches and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Bhuvnesh Jain , Justin Khoury

We consider different observational effects to test modified gravity approach involving the cosmological constant in the common description of the dark matter and the dark energy. We obtain upper limits for the cosmological constant by…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-19 A. Amekhyan , S. Sargsyan , A. Stepanian

In the past decade or so observations of supernovae, Large Scale Structures (LSS), and the Cosmic Microwave Background (CMB) have confirmed the presence of what is called dark energy - the cause of accelerating expansion of the Universe.…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-14 Houri Ziaeepour

After reviewing the modified Newtonian dynamics (MOND) proposal, we advocate that the associated phenomenology may actually not result from a modification of Newtonian gravity, but from a mechanism of "gravitational polarization" of some…

Astrophysics · Physics 2008-07-09 Luc Blanchet , Alexandre Le Tiec

Modified dark matter (MDM) is a phenomenological model of dark matter, inspired by gravitational thermodynamics. For an accelerating Universe with positive cosmological constant ($\Lambda$), such phenomenological considerations lead to the…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-14 Douglas Edmonds , Duncan Farrah , Djordje Minic , Y. Jack Ng , Tatsu Takeuchi

A type of exponential correction to General Relativity gives viable modified gravity model of dark energy. The model behaves as $R-2\Lambda$ at large curvature where an effective cosmological constant appears, but it becomes zero in flat…

General Relativity and Quantum Cosmology · Physics 2022-01-13 L. N. Granda

We present a class of modified-gravity theories which we call ultra-local models. We add a scalar field, with negligible kinetic terms, to the Einstein-Hilbert action. We also introduce a conformal coupling to matter. This gives rise to a…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 Philippe Brax , Luca Alberto Rizzo , Patrick Valageas

We explore observational constraints on possible deviations from Newtonian gravity by means of large-scale clustering of galaxies. We measure the power spectrum and the bispectrum of Sloan Digital Sky Survey galaxies and compare the result…

Astrophysics · Physics 2008-12-18 Akihito Shirata , Yasushi Suto , Chiaki Hikage , Tetsuya Shiromizu , Naoki Yoshida

We propose a relativistic gravitational theory leading to modified Newtonian dynamics, a paradigm that explains the observed universal galactic acceleration scale and related phenomenology. We discuss phenomenological requirements leading…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-18 Constantinos Skordis , Tom Zlosnik

A new class of modified gravity theories, made possible by subtle features of the canonical formulation of general covariance, naturally allows MOND-like behavior (MOdified Newtonian Dynamics) in effective space-time solutions without…

General Relativity and Quantum Cosmology · Physics 2023-11-01 Martin Bojowald , Erick I. Duque

Within the effective field theory approach to cosmic acceleration, the background expansion can be specified separately from the gravitational modifications. We explore the impact of modified gravity in a background different from a…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Guilherme Brando , Felipe T. Falciano , Eric V. Linder , Hermano E. S. Velten

The Special Issue on "Modified Gravity Approaches to the Tensions of $\Lambda$CDM"} in the Universe journal tackles significant challenges faced by the $\Lambda$CDM model, including discrepancies in the Hubble constant, growth rate of…

General Relativity and Quantum Cosmology · Physics 2024-04-23 Eleonora Di Valentino , Leandros Perivolaropoulos , Jackson Levi Said

An obvious criterion to classify theories of modified gravity is to identify their gravitational degrees of freedom and their coupling to the metric and the matter sector. Using this simple idea, we show that any theory which depends on the…

General Relativity and Quantum Cosmology · Physics 2017-03-01 Xavier Calmet , Iberê Kuntz