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相关论文: Linear perturbations spectra for dynamical dark en…

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The thermodynamics-gravity conjecture reveals that one can derive the gravitational field equations by using the first law of thermodynamics and vice versa. Considering the entropy associated with the horizon in the form of non-extensive…

广义相对论与量子宇宙学 · 物理学 2021-11-04 Mahnaz Asghari , Ahmad Sheykhi

Higher-order theories of gravity are a branch of modified gravity wherein the geometrodynamics of the four-dimensional Riemannian manifold is determined by field equations involving derivatives of the metric tensor of order higher than two.…

广义相对论与量子宇宙学 · 物理学 2024-04-19 R. R. Cuzinatto , L. G. Medeiros

In this paper, we propose a general form of the equation of state (EoS) which is the function of the fractional dark energy density $\Omega_{d}$. At least, five related models, the cosmological constant model, the holographic dark energy…

宇宙学与河外天体物理 · 物理学 2014-11-20 Yi Zhang , Hui Li

In order to validate or invalidate a large class of low energy effective theories, the Swampland conjecture has attracted significant attention, recently. It can be stated as inequalities on the potential of a scalar field which is…

高能物理 - 理论 · 物理学 2022-06-22 Phongpichit Channuie

Allowing for greater low-redshift flexibility through parametrizations such as CPL can lead to apparent deviations from $\Lambda$CDM, with the latter lying at roughly the $2\sigma$ level from the best-fit model. This motivates an…

宇宙学与河外天体物理 · 物理学 2026-04-21 Md. Wali Hossain

We investigate how the cosmological Equation of State can be used for scrutinizing extended theories of gravity, in particular, the Palatini $f(R)$ gravity. Specifically, the approach consists, at first, in investigating the effective…

广义相对论与量子宇宙学 · 物理学 2024-02-27 S. Camera , S. Capozziello , L. Fatibene , A. Orizzonte

We investigate the observational constraints on the modified gravity, which combines the $R^{2-q}$ inflation with the power-law (exponential) type of the viable $f(R)$ dark energy models. We discuss the difference between the combined model…

宇宙学与河外天体物理 · 物理学 2015-10-27 Chao-Qiang Geng , Chung-Chi Lee , Shan Lin

In this study, we investigate two dark energy models, MCJG and MCAG, in the context of $f(T)$ gravity within a non-flat FLRW Universe. Our analysis considers radiation, dark matter, and dark energy components. We compare the equation of…

广义相对论与量子宇宙学 · 物理学 2024-01-24 Himanshu Chaudhary , Ujjal Debnath , Tanusree Roy , Sayani Maity , G. Mustafa , Monika Arora

We combine complementary datasets from Cosmic Microwave Background (CMB) anisotropy measurements, high redshift supernovae (SN-Ia) observations and data from local cluster abundances and galaxy clustering (LSS) to constrain the dark energy…

天体物理学 · 物理学 2009-11-07 Rachel Bean , Alessandro Melchiorri

The Starobinsky model of modified gravity suggested to explain dark energy may be also considered in the astrophysical context. Recently it has been pointed out that in contracting regions curvature oscillations around the GR value may lead…

宇宙学与河外天体物理 · 物理学 2017-11-29 Dmitry Gorbunov , Anna Tokareva

We present a novel approach for reconstructing the $f(Q)$ gravitational theory using parameterizations of the deceleration parameter or alternative options. This method enables the development of modified gravity scenarios that align with…

广义相对论与量子宇宙学 · 物理学 2025-02-26 G. G. L. Nashed

In this work we have used the recent cosmic chronometers data along with the latest estimation of the local Hubble parameter value, $H_0$ at 2.4\% precision as well as the standard dark energy probes, such as the Supernovae Type Ia, baryon…

宇宙学与河外天体物理 · 物理学 2017-08-02 Weiqiang Yang , Narayan Banerjee , Supriya Pan

Motivated by the current status of the cosmological observations and significant tensions in the estimated values of some key parameters assuming the standard $\Lambda$CDM model, we propose a simple but radical phenomenological emergent…

宇宙学与河外天体物理 · 物理学 2020-01-14 Xiaolei Li , Arman Shafieloo

We update the constraints on the cosmological parameters by adopting the Planck data released in 2015 and Baryon Acoustic Oscillation (BAO) measurements including the new DR14 quasar sample measurement at redshift $z=1.52$, and we conclude…

宇宙学与河外天体物理 · 物理学 2017-12-06 Lu Chen , Qing-Guo Huang , Ke Wang

We study a power-law $F(R)$ gravity with an early dark energy term, that can describe both the early-time and the late-time acceleration of the Universe. We confront this scenario with recent observational data including the Pantheon Type…

广义相对论与量子宇宙学 · 物理学 2023-06-28 Sergei D. Odintsov , V. K. Oikonomou , German S. Sharov

Since the discovery of the accelerated expansion of the Universe in 1998, modified gravity (MG) theories have attracted considerable attention as alternatives to dark energy (DE). While distinguishing the effects of MG from those of DE…

宇宙学与河外天体物理 · 物理学 2025-01-16 Alejandro Aviles

Testing gravity and the concordance model of cosmology, $\Lambda$CDM, at large scales is a key goal of this decade's largest galaxy surveys. Here we present a comparative study of dark matter power spectrum predictions from different…

In this review we present a thoroughly comprehensive survey of recent work on modified theories of gravity and their cosmological consequences. Amongst other things, we cover General Relativity, Scalar-Tensor, Einstein-Aether, and Bimetric…

宇宙学与河外天体物理 · 物理学 2015-05-28 Timothy Clifton , Pedro G. Ferreira , Antonio Padilla , Constantinos Skordis

We highlight shortcomings of the dynamical dark energy (DDE) paradigm. For parametric models with equation of state (EOS), $w(z) = w_0 + w_a f(z)$ for a given function of redshift $f(z)$, we show that the errors in $w_a$ are sensitive to…

宇宙学与河外天体物理 · 物理学 2021-07-14 Eoin Ó Colgáin , M. M. Sheikh-Jabbari , Lu Yin

We study cosmological evolution in a flat FLRW spacetime in the context of modified STEGR gravity or $f(Q)$, using an exponential two-parameter model which represents a smooth perturbative expansion around the $\Lambda$CDM model. The…

广义相对论与量子宇宙学 · 物理学 2025-04-15 Ivan R. Vasquez , A. Oliveros
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