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In this investigation, we perform an observational statistical analysis in the theory of $ f(R, L_m) $ gravity. The proposed theoretical model is based on the Ricci scalar's non-linear contribution. We use a distinct parameterization for…

广义相对论与量子宇宙学 · 物理学 2024-08-30 J. K. Singh , Shaily , Akanksha Singh , Harshna Balhara , Joao R. L. Santos

We re-analyze the nonlocal gravity model of Deser and Woodard which was proposed to account for the current phase of cosmic acceleration. We show that the growth of perturbations predicted by this nonlocal gravity model when its background…

宇宙学与河外天体物理 · 物理学 2017-04-05 Sohyun Park , Arman Shafieloo

Strong lensing has developed into an important astrophysical tool for probing both cosmology and galaxies (their structures, formations, and evolutions). Now several hundreds of strong lens systems produced by massive galaxies have been…

宇宙学与河外天体物理 · 物理学 2015-05-28 Shuo Cao , Zong-Hong Zhu

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…

广义相对论与量子宇宙学 · 物理学 2020-06-15 Bruno J. Barros , Tiago Barreiro , Tomi Koivisto , Nelson J. Nunes

In this paper we present cosmological constraints on several well-known $f(R)$ models, but also on a new class of models that are variants of the Hu-Sawicki one of the form $f(R)=R-\frac{2\Lambda}{1+b\;y(R,\Lambda)}$, that interpolate…

宇宙学与河外天体物理 · 物理学 2018-01-29 Judit Pérez-Romero , Savvas Nesseris

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…

广义相对论与量子宇宙学 · 物理学 2024-04-23 Eleonora Di Valentino , Leandros Perivolaropoulos , Jackson Levi Said

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…

宇宙学与河外天体物理 · 物理学 2021-01-15 Guilherme Brando , Felipe T. Falciano , Eric V. Linder , Hermano E. S. Velten

We propose a new framework for studying the cosmology of $f(R)$ gravity which completely avoids using the reconstruction programme. This allows us to easily obtain a qualitative feel of how much the $\Lambda$CDM model differs from other…

广义相对论与量子宇宙学 · 物理学 2021-06-22 Saikat Chakraborty , Kelly MacDevette , Peter Dunsby

Recent studies by Sol\`a Peracaula, G\'omez-Valent, de Cruz P\'erez and Moreno-Pulido (2019,2020) have pointed out the intriguing possibility that Brans-Dicke cosmology with constant vacuum energy density (BD-$\Lambda$CDM) may be able to…

宇宙学与河外天体物理 · 物理学 2021-10-04 Adrià Gómez-Valent , Prajwal Hassan Puttasiddappa

We use observations related to the variation of fundamental constants, in order to impose constraints on the viable and most used $f(T)$ gravity models. In particular, for the fine-structure constant we use direct measurements obtained by…

广义相对论与量子宇宙学 · 物理学 2017-04-18 Rafael C. Nunes , Alexander Bonilla , Supriya Pan , Emmanuel N. Saridakis

In the last dozen years a wide and variegated mass of observational data revealed that the universe is now expanding at an accelerated rate. In the absence of a well-based theory to interpret the observations, cosmography provides…

宇宙学与河外天体物理 · 物理学 2015-09-30 Ester Piedipalumbo , Enrica Della Moglie , Roberto Cianci

Modified theories of gravity encompass a class of $f(R)$-models that seek to elucidate the observed late time accelerated expansion of the universe. In this study, we examine a set of viable $f(R)$ models (Hu-Sawicki: two cases,…

宇宙学与河外天体物理 · 物理学 2023-12-15 Kumar Ravi , Anirban Chatterjee , Biswajit Jana , Abhijit Bandyopadhyay

We use measurements of the galaxy-cluster angular size versus redshift to test and compare the standard model (LCDM) and the R_h=ct Universe. We show that the latter fits the data with a reduced chi^2_dof=0.786 for a Hubble constant H_0=…

宇宙学与河外天体物理 · 物理学 2018-09-25 Jun-Jie Wei , Xue-Feng Wu , Fulvio Melia

The longstanding search for the cosmological model that best describes the Universe has been made more intriguing since the recent discovery of the Hubble constant, $H_{0}$, tension observed between the value of $H_{0}$ from the Cosmic…

宇宙学与河外天体物理 · 物理学 2023-08-09 G. Bargiacchi , M. G. Dainotti , S. Capozziello

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…

广义相对论与量子宇宙学 · 物理学 2021-06-08 Grigoris Panotopoulos , Ángel Rincón

We study the evolution of linear perturbations in metric f(R) models of gravity and identify a potentially observable characteristic scale-dependent pattern in the behavior of cosmological structures. While at the background level viable…

天体物理学 · 物理学 2014-11-18 Levon Pogosian , Alessandra Silvestri

The discovery of the accelerated expansion of the universe highlighted General Relativity's inability to naturally account for dark energy without invoking a finely tuned cosmological constant. In response, a wide range of alternative…

广义相对论与量子宇宙学 · 物理学 2025-11-11 P. A. G. Monteiro , C. J. A. P. Martins

In this paper, we use a newly compiled sample of ultra-compact structure in radio quasars and strong gravitational lensing systems with quasars acting as background sources to constrain six spatially flat and non-flat cosmological models…

宇宙学与河外天体物理 · 物理学 2022-12-07 Tonghua Liu , Shuo Cao , Xiaolei Li , Hao Zheng , Yuting Liu , Wuzheng Guo , Chenfa Zheng

Modified gravity theories are a popular alternative to dark energy as a possible explanation for the observed accelerating cosmic expansion, and their cosmological tests are currently an active research field. Studies in recent years have…

宇宙学与河外天体物理 · 物理学 2016-10-12 Juan J. Ceron-Hurtado , Jian-hua He , Baojiu Li

We use three different data sets, specifically $H(z)$ measurements from cosmic chronometers, the HII-galaxy Hubble diagram, and reconstructed quasar-core angular-size measurements, to perform a joint analysis of three flat cosmological…

宇宙学与河外天体物理 · 物理学 2019-11-01 Hao-Yi Wan , Shu-Lei Cao , Fulvio Melia , Tong-Jie Zhang