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Related papers: Constraining the $f(R,T) = R + 2\lambda T$ cosmolo…

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In this paper, linear first order expansion of deceleration parameter $q(z)=q_0+q_1(1-a)$ ($M_1$), constant jerk $j=j_0$ ($M_2$) and third order expansion of luminosity distance ($M_3$) are confronted with cosmic observations: SCP 307 SN…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-24 Lixin Xu , Wenbo Li , Jianbo Lu

We reconstruct in this paper the deceleration and jerk parameters as functions of the cosmological redshift from data on cosmic chronometers (CCH), baryon acoustic oscillations (BAOs), and the Pantheon+MCT compilation of supernovae of Type…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-29 Adrià Gómez-Valent

We revisit the epoch of cosmic speed-up characterized by the redshift of transition from a decelerated to an accelerated phase. This redshift is termed the transition redshift ($z_t$). We use the spatially Flat and Non-Flat variants of the…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-02 David Dahiya , Deepak Jain

The Universe is currently in a phase of accelerated expansion, a fact that was experimentally proven in the late 1990s. Cosmological models involving scalar fields allow the description of this accelerated expansion regime in the Cosmos and…

General Relativity and Quantum Cosmology · Physics 2023-10-11 Joao R. L. Santos , S. Santos da Costa , Romario S. Santos

In this paper, we have explored the field equations of $f(T,B)$ gravity and determined the dynamical parameters with the hyperbolic function of Hubble parameter. The accelerating behavior has been observed and the behavior of equation of…

General Relativity and Quantum Cosmology · Physics 2022-07-22 S. A. Kadam , B. Mishra , S. K. Tripathy

In this paper, we investigate the possibility that the Universe is driven by a single dark fluid described by a Lambert $W$ equation of state parameter, $w_{eff}$, which is essentially dependent on two parameters $\vartheta_{1}$ and…

General Relativity and Quantum Cosmology · Physics 2022-02-14 Abdulla Al Mamon , Subhajit Saha

In this work, we investigate a cosmological scenario with a time-dependent cosmological constant $\Lambda$(t) within the spatially flat Friedmann-Lema\^itre-Robertson-Walker (FLRW) framework. Here we study a power-law $\Lambda(t)$CDM model…

General Relativity and Quantum Cosmology · Physics 2025-10-28 Archana Dixit , Manish Yadav , Anirudh Pradhan , M. S. Barak

We report on measurements of the cosmological constant, Lambda, and the redshift space distortion parameter beta=Omega_m^0.6/b, based on an analysis of the QSO power spectrum parallel and perpendicular to the observer's line of sight, from…

Astrophysics · Physics 2009-11-10 P. J. Outram , T. Shanks , B. J. Boyle , S. M. Croom , Fiona Hoyle , N. S. Loaring , L. Miller , R. J. Smith

In this work, the cosmic solutions, particularly the well-known $\Lambda$CDM model, are investigated in the framework of the Gauss-Bonnet gravity, where the gravitational action incorporates the Gauss-Bonnet invariant function. We utilize a…

General Relativity and Quantum Cosmology · Physics 2024-09-26 N. Myrzakulov , Anirudh Pradhan , Archana Dixit , S. H. Shekh

In this work, we investigate the cosmological consequences of an effective $f(Q)$ model emerging from the more general $f(Q,T)$ gravity theory under the special equation-of-state condition $\rho + p = 0$. Under this limit, the field…

General Relativity and Quantum Cosmology · Physics 2025-12-12 Anil Kumar Yadav , S. H. Shekh , N. Myrzakulov

Nowadays, efforts are being devoted to the study of alternative cosmological scenarios in which modifications of General Relativity have been proposed to explain the late cosmic acceleration without assuming the existence of dark energy. In…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-17 Bruno Ribeiro , Armando Bernui , Marcela Campista

In this manuscript, we have researched the cosmic expansion phenomenon in flat FRW Universe through the interaction of the recently proposed R$\grave{e}$nyi holographic dark energy (RHDE). For this reason, we assumed Hubble (H) and…

General Relativity and Quantum Cosmology · Physics 2021-08-02 Archana Dixit , Vinod Kumar Bhardwaj , Anirudh Pradhan

We investigate what current cosmological data tells us about the cosmological expansion rate in a model independent way. Specifically, we study if the expansion was decelerating at high redshifts and is accelerating now, without referring…

Astrophysics · Physics 2009-11-13 Edvard Mortsell , Chris Clarkson

We study the accelerated expansion phase of the universe by using the {\textit{kinematic approach}}. In particular, the deceleration parameter $q$ is parametrized in a model-independent way. Considering a generalized parametrization for…

General Relativity and Quantum Cosmology · Physics 2018-10-22 Abdulla Al Mamon , Kazuharu Bamba

The dynamics of perfect fluid as a source in the context of modified gravity, specifically $f(Q,T)$ gravity, are examined within the Friedmann-Lema\^itre-Robertson-Walker (FLRW) cosmological model. This gravity is a generic function of the…

General Relativity and Quantum Cosmology · Physics 2024-08-02 S. H. Shekh , Anirudh Pradhan , S. P. Gaikwad , K. R. Mule

The problem of cosmic acceleration and dark energy is one of the mysteries presently posed in the scientific society that general relativity has not been able to solve. In this work, we have considered alternative models to explain this…

General Relativity and Quantum Cosmology · Physics 2022-12-01 M. Koussour , N. Myrzakulov , S. H. Shekh , M. Bennai

A cosmological observable measured in a range of redshifts can be used as a probe of a set of cosmological parameters. Given the cosmological observable and the cosmological parameter, there is an optimum range of redshifts where the…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-07 L. Kazantzidis , L. Perivolaropoulos , F. Skara

Two parameters scale factor leading to bouncing cosmology is considered. We show that at some model parameters we obtain the deceleration parameter $q_0\approx -0.535$ at the current epoch which is in agreement with the Planck data. The…

General Physics · Physics 2026-05-18 S. I. Kruglov

Cosmology faces a pressing challenge with the Hubble constant ($H_0$) tension, where the locally measured rate of the Universe's expansion does not align with predictions from the cosmic microwave background (CMB) calibrated with…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-27 Rebecca Briffa , Celia Escamilla-Rivera , Jackson Levi Said , Jurgen Mifsud

A Friedmann like cosmological model in Einstein-Cartan framework is studied when the torsion function is assumed to be proportional to a single $\phi(t)$ function coming just from the spin vector contribution of ordinary matter. By…

General Relativity and Quantum Cosmology · Physics 2019-11-21 S. H. Pereira , R. de C. Lima , J. F. Jesus , R. F. L. Holanda
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