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Related papers: Quantitative constraints on modified gravity parad…

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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 apply the Union2 compilation of 557 supernova Ia data, the baryon acoustic oscillation measurement of distance, the cosmic microwave background radiation data from the seven year Wilkinson Microwave Anisotropy Probe, and the Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-27 Yungui Gong , Xiao-ming Zhu , Zong-Hong Zhu

Bimetric gravity is an interesting alternative to standard GR given its potential to provide a concrete theoretical framework for a ghost-free massive gravity theory. Here we investigate a class of Bimetric gravity models for their…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 Ajay Bassi , Shahnawaz A. Adil , Manvendra Pratap Rajvanshi , Anjan A. Sen

The observed accelerated expansion of the Universe may be explained by dark energy or the breakdown of general relativity (GR) on cosmological scales. When the latter case, a modified gravity scenario, is considered, it is often assumed…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-04 Jiro Matsumoto , Teppei Okumura , Misao Sasaki

In this work, we investigate Newtonian cosmologies with a time-varying gravitational constant, $G(t)$. We examine whether such models can reproduce the low-redshift cosmological observations without a cosmological constant, or any other…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-01 Ekim Taylan Hanımeli , Isaac Tutusaus , Brahim Lamine , Alain Blanchard

In this work, we developed a cosmological model in $ f(Q, C) $ gravity within the framework of symmetric teleparallel geometry. In addition to the non-metricity scalar $Q $, our formulation includes the boundary term $ C $, which accounts…

General Relativity and Quantum Cosmology · Physics 2024-11-12 Shaily , J. K. Singh , Mohit Tyagi , Joao R. L. Santos

In this work we perform an observational data analysis on the $f(R,T)$ gravity with the aim of constraining the parameter space of the model. Five different models are considered and the 30 point $z-H(z)$ cosmic chronometer data is used in…

General Relativity and Quantum Cosmology · Physics 2021-05-24 Prabir Rudra , Kinsuk Giri

We use the Allen et al. (2008) galaxy cluster gas mass fraction versus redshift data to constrain parameters of three different dark energy models: a cosmological constant dominated one ($\Lambda$CDM); the XCDM parameterization of dark…

Astrophysics · Physics 2010-11-11 Lado Samushia , Bharat Ratra

Regge-Teitelboim embedding gravity is the modified gravity based on a simple string-inspired geometrical principle: our spacetime is considered here as a 4-dimensional surface in a flat bulk. This theory is similar to the recently popular…

General Relativity and Quantum Cosmology · Physics 2020-10-13 S. A. Paston

Reconstructing the expansion history of the Universe from type Ia supernovae data, we fit the growth rate measurements and put model-independent constraints on some key cosmological parameters, namely, $\Omega_\mathrm{m},\gamma$, and…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-10 Benjamin L'Huillier , Arman Shafieloo , Hyungjin Kim

We explore the cosmological consequences of a modified cosmology inspired by string T-duality. We incorporate the zero-point length correction, $l_0$, into the gravitational potential and derive the modified Friedmann equations via…

General Relativity and Quantum Cosmology · Physics 2026-05-29 G. G. Luciano , A. Paliathanasis , A. Sheykhi

Astrophysical observations have put unprecedentedly tight constraints on cosmological theories. The $\Lambda$CDM model, mathematically simple and fits observational data-sets well, is preferred for explaining the behavior of universe. But…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Qiang Zhang , Guang Yang , Qixiang Zou , Xinhe Meng , Keji Shen

We provide a systematic and updated discussion of a research line carried out by our group over the last few years, in which gravity is modified at cosmological distances by the introduction of nonlocal terms, assumed to emerge at an…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-15 Enis Belgacem , Yves Dirian , Andreas Finke , Stefano Foffa , Michele Maggiore

In this manuscript, we investigate the constraints on dynamical vacuum models within the framework of $\Lambda(t)$CDM cosmology by assuming a parameterization of the vacuum energy density as $\rho_{\Lambda}(t)=\rho_{\Lambda 0} \left[1 +…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-14 Yerlan Myrzakulov , M. Koussour , M. Bulanbay , S. Muminov , J. Rayimbaev

We study constraints that anticipated DEEP survey galaxy counts versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant $\Lambda$. This data will result…

Astrophysics · Physics 2011-07-19 Silviu Podariu , Bharat Ratra

We probe the cosmic expansion scenario within the framework of $f(R, L_{m})$ gravity by employing a well-motivated functional form of $f(R, L_{m}) = \frac{R}{2} + L_{m}^{\lambda}$. Specifically, we introduce three novel cosmological models…

General Relativity and Quantum Cosmology · Physics 2026-05-27 Khomesh R. Patle , G. P. Singh

We study the redshift distribution of two samples of early-type gravitational lenses, extracted from a larger collection of 122 systems, to constrain the cosmological constant in the LCDM model and the parameters of a set of alternative…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Shuo Cao , Giovanni Covone , Zong-Hong Zhu

We extend and apply a model-independent analysis method developed earlier by Daly & Djorgovski to new samples of supernova standard candles, radio galaxy and cluster standard rulers, and use it to constrain physical properties of the dark…

In the framework of $f(Q)$ gravity, where gravity emerges from non-metricity $Q$, we explore the cosmological implications of its non-minimal coupling to matter. Inspired by the recent success of Chaplygin gas models in explaining dark…

General Relativity and Quantum Cosmology · Physics 2025-10-28 Nakul Aggarwal , Ali Pourmand , Fatimah Shojai , Harish Parthasarathy

Gravitational wave (GW) constraints have recently been used to significantly restrict models of dark energy and modified gravity. New bounds arising from GW decay and GW-induced dark energy instabilities are particularly powerful in this…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-25 Johannes Noller