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相关论文: A bridge between unified cosmic history by $f(R)$-…

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In this research, we propose a new model that allows to unify inflation, deceleration and acceleration phases of expansion history in BIonic system. In this model, in the beginning, there have been $k$ black fundamental strings that…

广义相对论与量子宇宙学 · 物理学 2015-05-20 Alireza Sepehri , Farook Rahaman , Mohammad Reza Setare , Anirudh Pradhan , Salvatore Capozziello , Iftikar Hossain Sardar

We study warm inflationary universe model on the BIon in thermal background. The BIon is a configuration in flat space of a D-brane and a parallel anti-D-brane connected by a wormhole with F-string charge. When the branes and antibranes are…

综合物理 · 物理学 2014-10-10 M. R. Setare , A. Sepehri

The cosmological reconstruction scheme for modified $F(R)$ gravity is developed in terms of e-folding (or, redshift). It is demonstrated how any FRW cosmology may emerge from specific $F(R)$ theory. The specific examples of well-known…

高能物理 - 理论 · 物理学 2014-11-20 Shin'ichi Nojiri , Sergei D. Odintsov , Diego Saez-Gomez

This study conducts a meticulous examination of the cosmological implications inherent in Rastall gravity and $f(R)$ gravity models, assessing their efficacy across distinct cosmic epochs, from early universe structure formation to…

广义相对论与量子宇宙学 · 物理学 2025-01-14 Muhammad Yarahmadi , Amin Salehi , Hadis Mousavi

The behavior of cosmological evolution is studied in the case when a phantom fluid, that contributes to the universe accelerated expansion, is introduced in an F (R) model. At the early stages of the universe history, the dark fluid is seen…

高能物理 - 理论 · 物理学 2011-07-18 Emilio Elizalde , Diego Sáez-Gómez

Recently, it has been proposed by Padmanabhan that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region leads to the expansion of the universe. Now, a natural…

广义相对论与量子宇宙学 · 物理学 2016-05-25 Alireza Sepehri , Farook Rahaman , Salvatore Capozziello , Ahmed Farag Ali , Anirudh Pradhan

We propose a strategy to infer the transition redshift $z_{da}$, which characterizes the passage through the universe decelerated to accelerated phases, in the framework $f(R)$ gravities. To this end, we numerically reconstruct $f(z)$, i.e.…

宇宙学与河外天体物理 · 物理学 2014-11-11 Salvatore Capozziello , Orlando Luongo

When a brane-anti-brane system includes two tachyons, each of them produces a BIoninc wormhole. These wormholes interact with each other and form 4 regions. Two of the regions are related to the independent BIons which have been considered…

高能物理 - 理论 · 物理学 2021-07-16 Aroonkumar Beesham

Recently, Padmanabhan [arXiv:1206.4916] argued that the expansion rate of the universe can be thought of as the emergence of space as cosmic time progresses and is related to the difference between the surface degrees of freedom on the…

广义相对论与量子宇宙学 · 物理学 2015-01-08 A. Sepehri , Farook Rahaman , Anirudh Pradhan , Iftikar Hossain Sardar

Observations from Supernovae Type Ia (SNe Ia) provided strong evidence for an expanding accelerating Universe at intermediate redshifts. This means that the Universe underwent a transition from deceleration to acceleration phases at a…

宇宙学与河外天体物理 · 物理学 2014-10-01 J. A. S. Lima , J. F. Jesus , R. C. Santos , M. S. S. Gill

Since viable $f(R)$ gravity models must reconcile early-universe inflation with late-time acceleration, we specifically study the dynamical behavior of such a theory during the matter-dominated to dark-energy-dominated transition epoch. By…

宇宙学与河外天体物理 · 物理学 2026-03-03 Siqi He , Weiqiang Yang , Hangyi Jin

We explore the late time cosmological dynamics of the Universe within the framework of $f(Q,\mathcal{L}_{m})$ gravity by considering the specific form $f(Q, \mathcal{L}_m)=-Q+2\mathcal{L}_m+\gamma$. To describe the cosmic pressure…

广义相对论与量子宇宙学 · 物理学 2025-08-08 Amit Samaddar , S. Surendra Singh

Braneworld models with variable brane tension $\lambda $ introduce a new degree of freedom that allows for evolving gravitational and cosmological constants, the latter being a natural candidate for dark energy. We consider a thermodynamic…

广义相对论与量子宇宙学 · 物理学 2011-03-28 K. C. Wong , K. S. Cheng , T. Harko

We have probed a cosmological model in $f(R)$-gravity, which is a cubic equation in scalar curvature $R$. The terms arise due to nonlinear $f(R)$ function are treated as energy due to curvature inspired geometry. As a result, we find…

广义相对论与量子宇宙学 · 物理学 2023-05-03 G. K. Goswami , Rita Rani , Harshna Balhara , J. K. Singh

We extract constraints on the transition redshift $z_{tr}$, determining the onset of cosmic acceleration, predicted by an effective cosmographic construction, in the framework of $f(T)$ gravity. In particular, employing cosmography we…

广义相对论与量子宇宙学 · 物理学 2015-06-19 Salvatore Capozziello , Orlando Luongo , Emmanuel N. Saridakis

It is accepted by the majority of scientific community that the Universe is currently in an accelerated epoch. In order to explain this shock of late 90's, a lot of dark energy candidates have been proposed. We study in the context of f (R)…

高能物理 - 理论 · 物理学 2014-11-20 Diego Sáez-Gómez

Some cosmological models based on the gravitational theory $f(R) = R+\zeta R^2$, and on fluids obeying to the equations of state of Redlich-Kwong, Berthelot, and Dieterici are proposed for describing smooth transitions between different…

广义相对论与量子宇宙学 · 物理学 2021-10-27 Saikat Chakraborty , Daniele Gregoris

We consider modified gravity which may describe the early-time inflation and/or late-time cosmic acceleration of the universe. In particular, we discuss the properties of $F(R)$, $F(G)$, string-inspired and scalar-Einstein-Gauss-Bonnet…

广义相对论与量子宇宙学 · 物理学 2013-06-20 Shin'Ichi Nojiri , Sergei D. Odintsov

We present a model of $F(R)$ gravity in the presence of a string theory motivated misalignment axion like particle materialized in terms of a canonical scalar field minimally coupled with gravity, and we study the cosmological phenomenology…

广义相对论与量子宇宙学 · 物理学 2020-02-19 S. D. Odintsov , V. K. Oikonomou

We examine the observational viability of a class of $f(\mathcal{R})$ gravity cosmological models. Particular attention is devoted to constraints from the recent observational determination of the redshift of the cosmological…

广义相对论与量子宇宙学 · 物理学 2015-06-19 Salvatore Capozziello , Omer Farooq , Orlando Luongo , Bharat Ratra
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