Statefinder diagnostic for modified Chaplygin gas cosmology in f(R,T) gravity with particle creation

In this paper, we have studied flat Friedmann--Lema\^{\i}tre--Robertson--Walker (FLRW) model with modified Chaplygin gas (MCG) having equation of state p_{m}=A\rho -% \frac{B}{\rho ^{\gamma }}, where $0\leq A\leq 1$, $0\leq \gamma \leq 1$ and $B$ is any positive constant in }${\footnotesize f(R,T)}${\footnotesize \ gravity with particle creation. We have considered a simple parametrization of the Hubble parameter $H$ in order to solve the field equations and discussed the time evolution of different cosmological parameters for some obtained models showing unique behavior of scale factor. We have also discussed the statefinder diagnostic pair $\{r,s\}$ that characterizes the evolution of obtained models and explore their stability. The physical consequences of the models and their kinematic behaviors have also been scrutinized here in some detail.Comment: 21 pages, 23 figures. arXiv admin note: text overlap with arXiv:1603.02573 by other author

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

An exact cosmological solution of Einstein 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 EFE. The cosmological dynamics of our model is discussed in detail. We have analyzed the time evolution of physical parameters and obtained their bounds analytically. Moreover, the behavior of these parameters are shown graphically in terms of redshift $`z'$. Our model is consistent with the formation of structure in the Universe. The role of the $f(R,T)$ coupling constant $\lambda$ 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.Comment: 21 PAGES, 20 FIGURE

FLRW cosmology with EDSFD parametrization

In this paper, we study a cosmological model in the background of Friedmann–Lemaitre–Robertson–Walker (FLRW) space time by assuming an appropriate parametrization in the form of a differential equation in terms of energy density of scalar field $$\rho _{\phi }$$, which is defined as Energy Density Scalar Field Differential equation (EDSFD) parametrization. The EDSFD parametrization leads to a required phase transition from early deceleration to present cosmic acceleration. This parametrization is used to reconstruct the equation of state parameter $$\omega _{\phi }$$ in terms of redshift z i.e. $$\omega _{\phi }(z)$$ to examine the evolutionary history of the universe in a flat FLRW space time. Here, we constrain the model parameter using the various observational datasets of Hubble parameter H(z) , latest Union 2.1 compilation dataset SNeIa, BAO, joint dataset $$H(z)+SNeIa$$ and $$H(z)+SNeIa+BAO$$ for detail analysis of the behavior of physical parameters and we find its best fit present value. Also, we discuss the dynamics of reheating phase after inflation, analyse the behaviors of the physical features using some diagnostic tools, and examine the viability of our parametric model