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相关论文: Constraining MOdified Gravity with the S2 Star

200 篇论文

In this letter, we investigate cosmology within the framework of modified $f(Q, L_m)$ gravity using the non-linear model $f(Q, L_m) = -Q + \alpha L_m^n + \beta$, where $\alpha$, $\beta$, and $n$ are free parameters. The modified Friedmann…

宇宙学与河外天体物理 · 物理学 2025-05-02 Y. Myrzakulov , Alnadhief H. A. Alfedeel , M. Koussour , S. Muminov , E. I. Hassan , J. Rayimbaev

As an alternative to dark matter models, MOdified Gravity (MOG) theory can compensate for dark matter by a covariant modification of Einstein gravity. The theory introduces two additional scalar fields and one vector field. The aim is to…

星系天体物理 · 物理学 2015-06-16 J. W. Moffat , S. Rahvar

A precise determination of the mass function is an important tool to verify cosmological predictions of the $\Lambda$CDM model and to infer more precisely the better model describing the evolution of the Universe. Galaxy clusters have been…

宇宙学与河外天体物理 · 物理学 2016-11-15 Ahmad Mehrabi , Francesco Pace , Mohammad Malekjani , Antonino Del Popolo

A possible gluon-condensate-induced modified-gravity model with f(R) \propto |R|^{1/2} has been suggested previously. Here, a simplified version is presented using the constant flat-spacetime equilibrium value of the QCD gluon condensate…

宇宙学与河外天体物理 · 物理学 2011-12-20 F. R. Klinkhamer

We investigate the imprints of the Generalized Uncertainty Principle on cosmological scales by using redshift-space distortion measurements in combination with background cosmological data to determine constraints on the deformation…

宇宙学与河外天体物理 · 物理学 2026-04-03 Andronikos Paliathanasis

We derive the main classical gravitational tests for a recently found vacuum solution with spin and dilation charges in the framework of Metric-Affine gauge theory of gravity. Using the results of the perihelion precession of the star S2 by…

广义相对论与量子宇宙学 · 物理学 2021-06-18 Sebastian Bahamonde , Jorge Gigante Valcarcel

We demonstrate that it is possible to test models of gravity, such as Palatini $f(R)$ and Eddington-inspired Born-Infeld models, using seismic data from Earth. By incorporating additional limitations on Earth's moment of inertia and mass…

广义相对论与量子宇宙学 · 物理学 2023-08-25 Aleksander Kozak , Aneta Wojnar

We determine the conditions for which the constraints from lunar laser ranging on the time evolution of the local gravitational constant can be extrapolated to impose constraints on the time evolution of the cosmological gravitational…

宇宙学与河外天体物理 · 物理学 2020-08-13 Clare Burrage , Johannes Dombrowski

We introduce methods which allow observed galaxy clustering to be used together with observed luminosity or stellar mass functions to constrain the physics of galaxy formation. We show how the projected two-point correlation function of…

星系天体物理 · 物理学 2016-03-02 Marcel P. van Daalen , Bruno M. B. Henriques , Raul E. Angulo , Simon D. M. White

Deviations from the standard $\Lambda$CDM model motivate an interpretation of early universe cosmology using the Scalar-Tensor-Vector-Gravity (STVG) theory. A constraint analysis carried out by Valentino, Melchiorri and Silk, revealed…

宇宙学与河外天体物理 · 物理学 2015-11-27 J. W. Moffat

In this paper we use a modification of the Newtonian gravitational potential with a non-linear Yukawa-like correction, as it was proposed by C. Will earlier to obtain new bounds on graviton mass from the observed orbits of S-stars around…

广义相对论与量子宇宙学 · 物理学 2024-04-16 Predrag Jovanović , Vesna Borka Jovanović , Duško Borka , Alexander F. Zakharov

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…

广义相对论与量子宇宙学 · 物理学 2022-01-13 L. N. Granda

We propose a modification of Einstein-Cartan gravity equations. The modified cosmology departs from the standard model of cosmology for small Hubble parameter. A characteristic Hubble scale h0, which is intrinsically related to cosmological…

广义相对论与量子宇宙学 · 物理学 2015-07-21 Wei Lu

It is well-known that allowing for spatial curvature affects constraints on cosmological parameters such as the dark energy equation of state parameters. Here we study the effect of curvature on constraints on parameters used to test…

宇宙学与河外天体物理 · 物理学 2013-05-30 Jason Dossett , Mustapha Ishak

We establish new constraints on $f(T)$ gravity models by using cosmological data. In particular, we investigate the restrictions given by the gas mass fraction measurements of galaxy clusters and transversal BAO data. Both data sets are…

宇宙学与河外天体物理 · 物理学 2022-09-28 F. B. M. dos Santos , J. E. Gonzalez , R. Silva

Modified gravity theories can introduce modifications to the Poisson equation in the Newtonian limit. As a result, we expect to see interesting features of these modifications inside stellar objects. White dwarf stars are one of the most…

广义相对论与量子宇宙学 · 物理学 2017-10-06 Srimanta Banerjee , Swapnil Shankar , Tejinder P. Singh

A novel function for modified gravity is proposed, $f(R, T)=R+\lambda R^2+2\beta\ln(T)$, with constants $\lambda$ and $\beta$, scalar curvature $R$, and the trace of stress energy tensor $T$, satisfying $T=\rho-3p>0$. Subsequently, two…

综合物理 · 物理学 2020-06-16 Emilio Elizalde , Nisha Godani , Gauranga C. Samanta

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…

宇宙学与河外天体物理 · 物理学 2024-03-04 Uendert Andrade , Abraão J. S. Capistrano , Eleonora Di Valentino , Rafael C. Nunes

We generalize Einstein's Lagrangian in a non-polynomial (in R) way. The usual Lagrangian (linear in R) is the zero $\alpha'$ limit of our theory, where $\alpha'$ is a parameter that is interpreted as the inverse cosmological costant before…

高能物理 - 理论 · 物理学 2008-02-03 C. Gasparakis

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…

宇宙学与河外天体物理 · 物理学 2013-10-01 Andrea Marchini , Valentina Salvatelli