Cosmological analysis of reconstructed 
                
                  
                
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Sharif, M.; Nazir, Kanwal

doi:10.1140/epjc/s10052-018-5572-z

“…Sharif and Nazir [36] investigated generalized ghost pilgrim DE in f (T ) gravity (T denotes torsion scalar) to prevent BH formulation. They also explored cosmic evolutionary regime of reconstructed f (T , T G ) models (T G indicates teleparallel equivalent to GB invariant) using different forms of scale factors [37]. Kleidis and Oikonomou [38] investigated entire cosmic evolutionary paradigm using scalar-tensor theory, specifically for single and two scalar theories.…”

Section: Introductionmentioning

confidence: 99%

Tsallis Holographic Dark Energy in f(G,T) Gravity

Sharif

¹

,

Saba

²

2019

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In this paper, we study the reconstruction paradigm for Tsallis holographic dark energy model using generalized Tsallis entropy conjecture with Hubble horizon in the framework of f ( G , T ) gravity (G and T represent the Gauss-Bonnet invariant and trace of the energy-momentum tensor). We take the flat Friedmann-Robertson-Walker universe model with dust fluid configuration. The cosmological evolution of reconstructed models is examined through cosmic diagnostic parameters and phase planes. The equation of the state parameter indicates phantom phase while the deceleration parameter demonstrates accelerated cosmic epoch for both conserved as well as non-conserved energy-momentum tensor. The squared speed of the sound parameter shows instability of the conserved model while stable non-conserved model for the entire cosmic evolutionary paradigm. The trajectories of the ω G T - ω G T ′ plane correspond to freezing as well as thawing regimes for the conserved and non-conserved scenario, respectively. The r - s plane gives phantom and quintessence dark energy epochs for conserved while Chaplygin gas model regime for the non-conserved case. We conclude that, upon the appropriate choice of the free parameters involved, the derived models demonstrate a self-consistent phantom universe behavior.

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“…Sharif and Nazir [31] analyzed the cosmological conditions of GGPDE with F(T , T g ) in terms of red-shift parameter. They considered power-law scale factor, scale factor for unified phases and intermediated scale factor to study the reconstructed models.…”

Section: Introductionmentioning

confidence: 99%

Evolution of non-flat cosmos via GGPDE f(R) model

Javed

¹

,

Nawazish

²

,

Shahid

³

et al. 2020

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This paper is devoted to explore the cosmic evolution of non-flat Friedmann Robertson Walker universe through generalized ghost pilgrim dark energy model in the background of f (R) gravity. For this purpose, we consider two well known scale factors, i.e., power-law and unified scale factors in terms of red shift parameter. For these scale factors, we reconstruct the given dark energy model in f (R) gravity and determine its stability/instability through squared speed of sound parameter. In order to discuss the behavior of reconstructed and dark energy models, we evaluate well known cosmological parameter such as equation of state parameter along with ω-ω plane. In addition to this, we also investigate compatibility of new models with standard cosmological models through state-finder parameters. The density parameter is formulated for both ordinary matter as well as dark energy components and results are compared with Planck 2018 constraints. It is concluded that cosmological parameters reveal consistency with recent observations while the value of density parameter suggested by Planck 2018 is achieved by power-law scale factor in most of the cases as compared to unified scale factor.

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Quark stars with 2.6 $$M_\odot $$ in a non-minimal geometry-matter coupling theory of gravity

Carvalho

¹

,

Lobato

²

,

Deb

³

et al. 2022

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This work analyses the hydrostatic equilibrium configurations of strange stars in a non-minimal geometry-matter coupling (GMC) theory of gravity. Those stars are made of strange quark matter, whose distribution is governed by the MIT equation of state. The non-minimal GMC theory is described by the following gravitational action: $$f(R,L)=R/2+L+\sigma RL$$ f ( R , L ) = R / 2 + L + σ R L , where R represents the curvature scalar, L is the matter Lagrangian density, and $$\sigma $$ σ is the coupling parameter. When considering this theory, the strange stars become larger and more massive. In particular, when $$\sigma =50$$ σ = 50 km$$^2$$ 2 , the theory can achieve the 2.6 $$M_\odot $$ M ⊙ , which is suitable for describing the pulsars PSR J2215+5135 and PSR J1614-2230, and the mass of the secondary object in the GW190814 event. The 2.6 $$M_\odot $$ M ⊙ is a value hardly achievable in General Relativity, even considering fast rotation effects, and is also compatible with the mass of PSR J0952-0607 ($$M = 2.35 \pm 0.17 ~M_\odot $$ M = 2.35 ± 0.17 M ⊙ ), the heaviest and fastest pulsar in the disk of the Milky Way, recently measured, supporting the possible existence of strange quark matter in its composition. The non-minimal GMC theory can also give feasible results to describe the macroscopical features of strange star candidates.

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Cosmological analysis of reconstructed $${\mathcal {F}}(T,T_{\mathcal {G}})$$ F ( T , T G ) models

Cited by 6 publications

References 28 publications

Tsallis Holographic Dark Energy in f(G,T) Gravity

Tsallis Holographic Dark Energy in f(G,T) Gravity

Evolution of non-flat cosmos via GGPDE f(R) model

Quark stars with 2.6 $$M_\odot $$ in a non-minimal geometry-matter coupling theory of gravity

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