Inflation in terms of a viscous van der Waals coupled fluid

Brevik, Iver; Обухов, В. В.; Тимошкин, А. В.

doi:10.1142/s0219887818501505

Cited by 21 publications

(20 citation statements)

References 36 publications

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“…After the discovery of acceleration of the Universe, the concept of viscous cosmology has been reconsidered again. Some recent papers provide an application of viscous cosmology to the accelerating Universe [35,36]. For an isotropic and homogeneous cosmic expansion, the negative pressure of a bulk viscous fluid might play the role of an exotic fluid and could account for the effects usually attributed to DE.…”

Section: Introductionmentioning

confidence: 99%

Analysis with observational constraints in $$ \Lambda $$ Λ -cosmology in f(R, T) gravity

et al. 2018

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An exact cosmological solution of Einstein's field equations (EFEs) is derived for a dynamical vacuum energy in f (R, T) gravity for Friedmann-Lemaitre-Robertson-Walker (FLRW) space-time. A parametrization of the Hubble parameter is used to find a deterministic solution of the EFE. The cosmological dynamics of our model is discussed in detail. We have analyzed the time evolution of the physical parameters and obtained their bounds analytically. Moreover, the behavior of these parameters are shown graphically in terms of the redshift 'z'. Our model is consistent with the formation of structure in the Universe. The role of the f (R, T) coupling constant λ is discussed in the evolution of the equation of state parameter. The statefinder and Om diagnostic analysis is used to distinguish our model with other dark energy models. The maximum likelihood analysis has been reviewed to obtain the constraints on the Hubble parameter H 0 and the model parameter n by taking into account the observational Hubble data set H (z), the Union 2.1 compilation data set SNeIa, the Baryon Acoustic Oscillation data BAO, and the joint data set H (z) + SNeIa and H (z) + SNeIa + BAO. It is demonstrated that the model is in good agreement with various observations.

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Section: Introductionmentioning

confidence: 99%

Analysis with observational constraints in $$ \Lambda $$ Λ -cosmology in f(R, T) gravity

et al. 2018

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“…where a 0 is the current value of the scale factor. Here we can see that collisional matter can be described by Equations (15) and (19). In addition, Π 0 has the value…”

Section: Collisional Matter Model Within F (R T) Theory and Late-timmentioning

confidence: 82%

“…where p m is the pressure for collisional matter and p r is the pressure from radiation. By using Equations (15) and (19), we can rewrite Equation (21) in the following form:…”

Section: Collisional Matter Model Within F (R T) Theory and Late-timmentioning

confidence: 99%

“…As we already mentioned, a consistent way to model the dark energy and the early-time acceleration era is to use the modified gravity theoretical framework [5,6,[11][12][13][14][15][16]. However, alternative approaches can also describe these acceleration epochs [17][18][19]. Modified gravity models are generally modifications of the general relativity (GR) picture.…”

Section: Introductionmentioning

confidence: 99%

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Impact of Collisional Matter on the Late-Time Dynamics of f(R,T) Gravity

et al. 2018

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We study the cosmic evolution of non-minimally coupled f ( R , T ) gravity in the presence of matter fluids consisting of collisional self-interacting dark matter and radiation. We study the cosmic evolution in the presence of collisional matter, and we compare the results with those corresponding to non-collisional matter and the Λ -cold-dark-matter ( Λ CDM) model. Particularly, for a flat Friedmann–Lema i ^ tre–Robertson–Walker Universe, we study two non-minimally coupled f ( R , T ) gravity models and we focus our study on the late-time dynamical evolution of the model. Our study is focused on the late-time behavior of the effective equation of the state parameter ω e f f and of the deceleration parameter q as functions of the redshift for a Universe containing collisional and non-collisional dark matter fluids, and we compare both models with the Λ CDM model. As we demonstrate, the resulting picture is well accommodated to the latest observational data on the basis of physical parameters.

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“…Therefore, several steps have been taken in physics. Non-linearity and Inhomogeneity in cosmic fluid are some of them [7,40].…”

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confidence: 99%

Thermodynamic analysis for Non-linear system (Van-der-Waals EOS) with viscous cosmology

2021

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The following paper is motivated by the recent works of Kremer [Gen Relativ Gravit 36(6):1423–1432, 2004; Phys Rev D 68(12):123507, 2003], Vardiashvili (Inflationary constraints on the van Der Waals equation of state, arXiv:1701.00748, 2017), Jantsch (Int J Mod Phys D 25(03):1650031, 2016), Capozziello (Phys Lett A 299(5–6):494–498, 2002) on Van-Der-Waals EOS cosmology. The main aim of this paper is to analyze the thermodynamics of a Non-linear system which in this case is Van-Der-Waals fluid EOS (Capozziello et al., Quintessence without scalar fields, arXiv:astro-ph/0303041, 2003). We have investigated the Van-Der-Waals fluid system with the generalized EOS as $$p=w\left( \rho ,t \right) \rho +f\left( \rho \right) -3\eta \left( H,t \right) H$$ p = w ρ , t ρ + f ρ - 3 η H , t H (Brevik et al., Int J Geom Methods Mod Phys 15(09):1850150, 2018). The third term signifies viscosity which has been considered as an external parameter that only modifies pressure but not the density of the liquid. The $$w(\rho ,t)$$ w ( ρ , t ) and $$f(\rho )$$ f ( ρ ) are the two functions of energy density and time that are different for the 3 types of Vander Waal models namely one parameter model, two parameters model and three parameters model (Ivanov and Prodanov, Eur Phys J C 79(2):118, 2019; Elizalde and Khurshudyan, Int J Mod Phys D 27(04):1850037, 2018). The value of EOS parameter ($$w_{EOS})$$ w EOS ) (Capozziello et al., Quintessence without scalar fields, arXiv:astro-ph/0303041, 2003; Obukhov and Timoshkin, Russ Phys J 60(10):1705–1711, 2018) will showdifferent values for different models. We have studied the changes in the parameters for different cosmic phases [Kremer, Phys Rev D 68(12):123507, 2003; Capozziello et al., Phys Lett A 299(5–6):494–498, 2002; Capozziello et al., Quintessence without scalar fields, arXiv:astro-ph/0303041, 2003]. We have also studied the thermodynamics and the stability conditions for the three models in viscous condition [Obukhov and Timoshkin, Russ Phys J 60(10):1705–1711, 2018; Panigrahi and Chatterjee, Gen Relativ Gravit 49(3):35, 2017; Panigrahi and Chatterjee, J Cosmol Astropart Phys 2016(05):052, 2016; Chakraborty et al., Evolution of FRW Universe in Variable Modified Chaplygin Gas Model, arXiv:1906.12185, 2019]. We have discussed the importance of viscosity (Brevik and Grøn, Astrophys Space Sci 347(2):399–404, 2013) in explaining accelerating universe with negative pressure (Panigrahi and Chatterjee, Gen Relativ Gravit 49(3):35, 2017).Finally, we have resolved the finite time future singularity problems [Brevik et al., The effect of thermal radiation on singularities in the Dark Universe, arXiv:2103.08430, 2021; Odintsov and Oikonomou, Phys Rev D 98(2):024013, 2018; Odintsov and Oikonomou, Int J Mod Phys D 26(08):1750085, 2017; Frampton et al., Phys Rev D 85(8):083001, 2012; Frampton et al., Phys Lett B 708(1–2):204–211, 2012; Frampton et al., Phys Rev D 84(6):063003, 2011] and discussed the thermodynamics energy conditions [Visser and Barcelo, Energy conditions and their cosmological implications. In: Cosmo-99, pp 98–112, 2000; Chattopadhyay et al., Eur Phys J C 74(9):1–13, 2014; Arora et al., Phys. Dark Universe 31:100790, 2021; Sharma and Pradhan, Int J Geom Methods Mod Phys 15(01):1850014, 2018; Sahoo et al., AstronomischeNachrichten 342(1–2):89–95, 2021; Yadav et al., Mod Phys Lett A 34(19):1950145, 2019; Sharma et al., Int J Geom Methods Mod Phys 17(07):2050111, 2020, Moraes and Sahoo, Eur Phys J C 77(7):1–8, 2017; Hulke et al., New Astron 77:101357, 2020; Singla et al., Gravit Cosmol 26(2):144–152, 2020; Sharif et al., Eur Phys J Plus 128(10):1–11, 2013] with those models.

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Inflation in terms of a viscous van der Waals coupled fluid

Cited by 21 publications

References 36 publications

Analysis with observational constraints in $$ \Lambda $$ Λ -cosmology in f(R, T) gravity

Analysis with observational constraints in $$ \Lambda $$ Λ -cosmology in f(R, T) gravity

Impact of Collisional Matter on the Late-Time Dynamics of f(R,T) Gravity

Thermodynamic analysis for Non-linear system (Van-der-Waals EOS) with viscous cosmology

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