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Related papers: Constraining viscous fluid models in $f(Q)$ gravit…

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In this manuscript, we studied the accelerated expansion history of the universe and the formations of large-scale structures using $f(Q)$ gravity model. The expansion rate of the universe within distance modulus and redshift has been…

General Relativity and Quantum Cosmology · Physics 2022-06-07 Shambel Sahlu , Endalkachew Tsegaye

Locally-rotationally-symmetric Bianchi type-I viscous and non -viscous cosmological models are explored in general relativity (GR) and in f(R,T) gravity. Solutions are obtained by assuming that the expansion scalar is proportional to the…

General Relativity and Quantum Cosmology · Physics 2021-07-07 S. Jokweni , Vijay Singh , Aroonkumar Beesham

In this paper, we investigate the effects of varying bulk viscosity coefficients $\zeta(t)=\zeta_{0}+\zeta_{1}H$ on cosmic evolution within the framework of $f(T)$ teleparallel gravity. We focus on two cases: (i) $\zeta_{1} \neq0$ and (ii)…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-14 Kairat Myrzakulov , O. Donmez , M. Koussour , S. Muminov , E. Davletov , J. Rayimbaev

We take into account redshift-space distortion measurements to investigate the growth of cosmological large-scale structures within the framework of modified symmetric teleparallel $f(Q)$ gravity. After comparing the predictions of the…

General Relativity and Quantum Cosmology · Physics 2025-03-20 Shambel Sahlu , Álvaro de la Cruz-Dombriz , Amare Abebe

In this article, we have discussed the results of our investigation. We consider an anisotropic viscous cosmological model of (LRS) Bianchi type I spacetime universe filled with a viscous fluid under $f(Q)$ gravity. We have studied the…

General Relativity and Quantum Cosmology · Physics 2024-08-14 Anirudh Pradhan , Archana Dixit , Dinesh Chandra Maurya

Recent studies indicate that, near equilibrium condition could not be maintained for bulk viscous matter models during the accelerated expansion of the universe in the context of Einstein's gravity, without including the cosmological…

General Relativity and Quantum Cosmology · Physics 2023-03-28 Vishnu A Pai , Titus K Mathew

In this paper, we observationally test the \( f(Q) \) gravity model at both background and perturbation levels using Pantheon$^+$, Hubble measurements, and Redshift Space Distortion Data. We obtain the best-fit parameters by solving…

General Relativity and Quantum Cosmology · Physics 2024-11-08 Dalale Mhamdi , Farida Bargach , Safae Dahmani , Amine Bouali , Taoufik Ouali

Inspired by an exponential $f(R)$ gravity model studied in the literature, in this work we introduce a new and viable $f(Q)$ gravity model, which can be represented as a perturbation of $\Lambda$CDM. Typically, within the realm of $f(Q)$…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-31 A. Oliveros , Mario A. Acero

In the last century, theoretical and experimental developments have established the General Relativity theory as the most successful theory for describing the gravitational phenomenon. On the other hand, in the last two decades, multiple…

General Relativity and Quantum Cosmology · Physics 2025-02-18 Raja Solanki

In this paper, we have studied the late-time accelerating expansion of the Universe using the matter-geometry coupled $ f(Q, T) $ gravity model, where $ Q $ is the non-metricity scalar and $ T $ represents the trace of the energy-momentum…

General Relativity and Quantum Cosmology · Physics 2025-03-03 Shambel Sahlu , Bhupendra Kumar Shukla , Rishi Kumar Tiwari , Değer Sofuoğlu , Alnadhief H. A. Alfedeel

In this work, in the framework of dynamical system analysis, we focus on the study of the accelerated expansion of the Universe of $f(Q)$ gravity theory where $Q$ be the non-metricity that describes the gravitational interaction. We…

General Relativity and Quantum Cosmology · Physics 2023-02-07 Amit Samaddar , S. Surendra Singh , Shivangi Rathore

In this study, we examined the late-time cosmic expansion of the universe within the framework of $f(Q, L_m)$ gravity, where $Q$ denotes the non-metricity and $L_{m}$ represents the matter Lagrangian. We analyzed a linear $f(Q, L_m)$ model…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-15 Yerlan Myrzakulov , O. Donmez , M. Koussour , D. Alizhanov , S. Bekchanov , J. Rayimbaev

In the past few years, $f(Q)$ theories have drawn a lot of research attention in replacing Einstein's theory of gravity successfully. The current study examines the novel cosmological possibilities emerging from two specific classes of…

General Relativity and Quantum Cosmology · Physics 2023-05-31 M. Koussour , Avik De

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

In this paper we present two concrete models of non-perfect fluid with bulk viscosity to interpret the observed cosmic accelerating expansion phenomena, avoiding the introduction of exotic dark energy. The first model we inspect has a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Xin-he Meng , Zhi-yuan Ma

This thesis explores the cosmological implications of modified gravity, focusing on nonmetricity-based $f(Q)$ gravity as an alternative to the $\Lambda$CDM model in explaining cosmic acceleration. Chapter I lays the theoretical groundwork…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Gaurav N. Gadbail

In this paper, we introduce bulk viscosity in the formalism of modified gravity theory in which the gravitational action contains a general function $f(R,T)$, where $R$ and $T$ denote the curvature scalar and the trace of the…

General Relativity and Quantum Cosmology · Physics 2015-03-02 C. P. Singh , Pankaj Kumar

We study a cosmological model composed of a dark energy fluid interacting with a viscous matter fluid in a spatially flat Universe. The matter component represents the baryon and dark matter and it is taken into account, through a bulk…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Arturo Avelino

We study the cosmological implications of barotropic fluid satisfying affine equation of state (EoS) in the General relativity and $f(Q)$ gravity framework. We describe the impact of affine EoS on the cosmic evolution in the model and…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Romanshu Garg , G. P. Singh , Ashutosh Singh

Within the $f(Q)$-gravity framework we perform a phenomenological study of the cosmological observables in light of the degeneracy between neutrinos physics and the modified gravity parameter and we identify specific patterns which allow to…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 Luís Atayde , Noemi Frusciante