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Related papers: Reconstructing cosmic expansion in $f(R, G)$ gravi…

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We explore a cosmological model based on R\'enyi entropic corrections to the Friedmann equations and constrain it using DESI, P-BAO, CC, and gravitational-wave observations. Unlike earlier works, we obtain a direct and stringent constraint…

General Relativity and Quantum Cosmology · Physics 2026-04-27 Rajdeep Mazumdar , Kalyan Malakar , Kalyan Bhuyan

We scrutinized the Locally Rotational Symmetry (LRS) Bianchi type-I cosmological model in the presence of fractional holographic dark energy. We calculate the value of the Hubble parameter $H(z)$ using the field equations. After that, we…

General Relativity and Quantum Cosmology · Physics 2025-06-23 Shivangi Rathore , Elangbam Chingkheinganba Meetei , S. Surendra Singh

In the Friedmann cosmology the deceleration of the expansion $q$ plays a fundamental role. We derive the deceleration as a function of redshift $q(z)$ in two scenarios: $\Lambda$CDM model and modified Chaplygin gas ($MCG$) model. The…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-12 Alan M. Velásquez-Toribio , Maria Luíza Bedran

For different gravitational models we consider limitations on their parameters coming from recent observational data for type Ia supernovae, baryon acoustic oscillations, and from 34 data points for the Hubble parameter $H(z)$ depending on…

General Relativity and Quantum Cosmology · Physics 2014-11-06 G. S. Sharov , E. G. Vorontsova

The present work deals with kinematical models of latetime cosmology. It is based on purely phenomenological assumption about the deceleration parameter. The models are confronted to observational data sets of type Ia supernovae distance…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-12 Ankan Mukherjee

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

In this article, we investigate the modified symmetric teleparallel gravity or $f(Q)$ gravity, where $Q$ is the non-metricity, to study the evolutionary history of the universe by considering the functional form of $f(Q)=\alpha Q^n$, where…

General Relativity and Quantum Cosmology · Physics 2022-12-16 Gaurav N. Gadbail , Sanjay Mandal , P. K. Sahoo

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…

General Relativity and Quantum Cosmology · Physics 2024-08-30 J. K. Singh , Shaily , Akanksha Singh , Harshna Balhara , Joao R. L. Santos

Combining the kinematical definitions of the two dimensionless parameters, the deceleration q(x) and the Hubble t0H(x), we get a differential equation (where x = t/t0 is the age of the universe relative to its present value t0). First…

General Physics · Physics 2012-01-17 Antonio Alfonso-Faus

In the recently suggested modified non-metricity gravity theory with boundary terms in a flat FLRWspacetime universe, dark energy scenarios of cosmological models are examined in this study. An arbitrary function, $f(Q, C)=Q+{\alpha}C^{2}$,…

General Relativity and Quantum Cosmology · Physics 2023-10-05 Anirudh Pradhan , Archana Dixit , M. Zeyauddin , S. Krishnannair

Cosmic chronometers offer a model-independent way to trace the expansion history of the Universe via the dating of passively evolving objects. This enables testing the validity of cosmological models without concrete assumptions of their…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-05 Carlos A. Álvarez , Marcos M. Cueli , Alessandro Bressan , Lumen Boco , Balakrishna S. Haridasu , Michele Bosi , Luigi Danese , Andrea Lapi

Class of spherically symmetric Stephani cosmological models is examined in the context of evolution type. It is assumed that the equation of state at the symmetry center of the models is barotropic. Classification of cosmological models is…

Astrophysics · Physics 2009-11-13 Izabela Jakacka , Jerzy Stelmach

A spatially homogeneous anisotropic LRS Bianchi type-I cosmological model is studied in $f(R,T)$ gravity with a special form of Hubble's parameter, which leads to constant deceleration parameter. The parameters involved in the considered…

General Relativity and Quantum Cosmology · Physics 2022-07-20 Binaya K. Bishi , S. K. J. Pacif , P. K. Sahoo , G. P. Singh

Our objective in this paper is to study the late-time behavior of the universe in a model resulting from a parametrization of the Hubble parameter ($H$) in $f(Q,T)$ gravity. We have considered the flat Friedmann-Lemaitre-Robertson-Walker…

General Relativity and Quantum Cosmology · Physics 2023-04-19 Viraj Kalsariya , Shibesh Kumar Jas Pacif

We explore the viability of three models in $f(T,B)$ gravity using data from recent surveys based on cosmic chronometers, the Pantheon data set, and baryonic acoustic oscillation data. We also assess the consistency of these models and data…

General Relativity and Quantum Cosmology · Physics 2022-12-23 Rebecca Briffa , Celia Escamilla-Rivera , Jackson Levi Said , Jurgen Mifsud

Using the mathematical definitions of deceleration and jerk parameters we obtain a general differential equation for squared Hubble parameter. For a constant jerk, this differential equation leads to an exact function for Hubble parameter.…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-21 Hassan Amirhashchi , Soroush Amirhashchi

This paper examines the late-time accelerating Universe and the formation of large-scale structures within the modified symmetric teleparallel gravity framework, specifically using the $f(Q)$-gravity model, in light of recent cosmological…

General Relativity and Quantum Cosmology · Physics 2024-12-31 Shambel Sahlu , Amare Abebe

We revisit the kink-like parametrization of the deceleration parameter q(z), which considers a transition, at $z_t$, from cosmic deceleration to acceleration. In this parametrization the initial, at $z \gg z_t$, value of the q-parameter is…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-01 Marcelo Vargas dos Santos , Ribamar R. R. Reis , Ioav Waga

We study the evolution of the cosmological parameters, namely, the deceleration parameter $q(z)$ and the parameter of effective equation of state in a universe contains, besides the ordinary matter and dark energy, a self-interacting…

General Relativity and Quantum Cosmology · Physics 2015-11-04 E. H. Baffou , M. J. S. Houndjo , M. E. Rodrigues , A. V. Kpadonou , J. Tossa

We investigate a fourth order model of gravity, having a free length parameter, and no cosmological constant or dark energy. We consider cosmological evolution of a flat Friedmann universe in this model for the case that the length…

General Relativity and Quantum Cosmology · Physics 2015-10-14 Shreya Banerjee , Nilesh Jayswal , Tejinder P. Singh