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In the current study, we investigate a scalar field cosmological model with Lyra's geometry to explain the present cosmic expansion in a homogeneous and isotropic flat FRW universe. In Einstein's field equations, we presupposed a variable…

General Relativity and Quantum Cosmology · Physics 2025-11-19 Vinod Kumar Bhardwaj , Anil Kumar Yadav , Lalit Kumar Gupta , Rajendra Prasad , Sudhir Kumar Srivastava

We here propose a new class of barotropic factor for matter, motivated by properties of isotropic deformations of crystalline solids. Our approach is dubbed Anton-Schmidt's equation of state and provides a non-vanishing, albeit small,…

General Relativity and Quantum Cosmology · Physics 2017-12-13 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

By way of a complete integration of the Friedmann equations, in terms of observables, it is shown that for the cosmological constant $\Lambda > 0$ there exist non-flat FLRW models for which the total density parameter $\Omega$ remains $\sim…

Astrophysics · Physics 2009-11-10 Kayll Lake

We revisit a cosmological model where dark matter (DM) and dark energy (DE) follow barotropic equations of state, allowing deviations from the standard $\Lambda$CDM framework (i.e. $w_{dm} \neq 0$, $w_{de} \neq -1$), considering both flat…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-24 Dorian Araya , Cristian Castillo , Genly Leon , Juan Magaña , Angie Barr Domínguez , Miguel A. García-Aspeitia

We consider ever-expanding Big Bang models with a cosmological constant, $\Lambda$, and investigate in detail the evolution of the observable part of the universe. We also discuss quintessence models from the same point of view. A new…

Astrophysics · Physics 2009-11-06 Einar H. Gudmundsson , Gunnlaugur Bjornsson

This study investigates the potential of a cosmological model termed $\Lambda w$DM, in which a cosmological constant play the role of dark energy and dark matter is barotropic and has a constant equation of state parameter ($w_{\rm dm}$),…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-02 Yan-Hong Yao , Jian-Qi Liu

Discrepancies between distance measurements and $\Lambda$CDM predictions reveal notable features in the distance-redshift relation, possibly suggesting the presence of an evolving dark energy component. Given the central role of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-06 David Camarena , Kylar Greene , John Houghteling , Francis-Yan Cyr-Racine

In this work, we assume the FRLW Universe which is filled with dark matter along with dark energy in the framework of Horava-Lifshitz (HL) gravity. The dark energy is considered as the Linear (Model I) and CPL (Model II) parametrizations of…

General Relativity and Quantum Cosmology · Physics 2024-02-07 Himanshu Chaudhary , Niyaz Uddin Molla , Madhur Khurana , Ujjal Debnath , G. Mustafa

Recent cosmological observations show hints for possible deviations from the standard $\Lambda$CDM paradigm at late times. To study such deviation, we introduce a minimal phenomenological framework in which the total equation of state of…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Shibendu Gupta Choudhury , Anjan A Sen

In a thermodynamical model of cosmological FLRW event horizons for the dark energy (DE), we consider a logarithmic corrective term in the entropy to which corresponds a new term in the DE density. This model of $\Lambda (t)$ in an…

Astrophysics · Physics 2016-08-15 Cécile Barbachoux , Jérome Gariel , Gérard Le Denmat

This paper explores models of the FLRW universe that incorporate a time-varying cosmological term $\Lambda(t)$. Specifically, we assume a power-law form for the cosmological term as a function of the scale factor: $\Lambda(t)=\Lambda_{0}…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-14 M. Koussour , N. Myrzakulov , J. Rayimbaev

A new kind of accelerating flat model with no dark energy that is fully dominated by cold dark matter (CDM) is investigated. The number of CDM particles is not conserved and the present accelerating stage is a consequence of the negative…

Astrophysics · Physics 2014-11-18 J. A. S. Lima , F. E. Silva , R. C. Santos

Redshift drift is the phenomenon whereby the observed redshift between an emitter and observer comoving with the Hubble flow in an expanding FLRW universe will slowly evolve -- on a timescale comparable to the Hubble time. In a previous…

General Relativity and Quantum Cosmology · Physics 2024-04-03 Francisco S. N. Lobo , José Pedro Mimoso , Jessica Santiago , Matt Visser

In the present work, flat FRW model of the universe is considered to be an isolated open thermodynamical system where non-equilibrium prescription has been studied using the mechanism of particle creation. In the perspective of recent…

General Physics · Physics 2016-05-17 Subhajit Saha , Atreyee Biswas , Subenoy Chakraborty

In this work, we have considered the flat FRW model of the universe in $(n+2)$-dimensions filled with the dark matter (perfect fluid with negligible pressure) and the modified Chaplygin gas (MCG) type dark energy. We present the Hubble…

General Physics · Physics 2015-09-09 Chayan Ranjit , Shuvendu Chakraborty , Ujjal Debnath

We consider the holographic Friedman-Robertson-Walker (hFRW) universe on the 4-dimensional membrane embedded in the 5-dimensional bulk spacetime and fit the parameters with the observational data. In order to fully account for the…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-09 Da Huang , Bum-Hoon Lee , Gansukh Tumurtushaa , Lu Yin , Yun-Long Zhang

The standard LambdaCDM model of cosmology is usually understood to arise from demanding that the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric satisfy the General Relativity dynamics for spacetime metrics. The FLRW data-based dominant…

General Physics · Physics 2009-07-13 Reginald T Cahill

On the basis of a previously established scalar-tensor extension of the $\Lambda$CDM model we develop an effective fluid approach for the matter growth function. This extended $\Lambda$CDM (henceforth $e_{\Phi}\Lambda$CDM) cosmology takes…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-01 W. Zimdahl , H. E. S. Velten , W. C. Algoner

We investigate late-time cosmology in the context of modified $f(Q,L_m)$ gravity, considering a non-linear model$ f(Q,L_m) = \alpha Q + \beta L_m^n + \lambda$ where, $\alpha$, $\beta$, $\lambda$, and $n$ are some free parameters. The…

General Relativity and Quantum Cosmology · Physics 2026-01-16 Rajdeep Mazumdar , Kalyan Malakar , Kalyan Bhuyan

In this paper We have investigated a homogeneous and isotropic FRW cosmological model with perfect fluid in the framework of $f(R,Lm)$ gravity. We have explored for the non linear case of $f(R,L_m)$ model, namely $f(R,L_m) = R/2 + L_m$ and…

General Relativity and Quantum Cosmology · Physics 2023-06-19 Bhupendra Kumar Shukla , Rishi KumarTiwari , Deger Sufuoglu , Aroonkumar Beesham