Study of Some Cosmological Parameters for Interacting New Holographic Dark Energy Model in f(T) Gravity

The present work is based on the idea of an interacting framework of new holographic dark energy with cold dark matter in the background of $f(T)$ gravity. Here, we have considered the flat modified Friedmann universe for $f(T)$ gravity which is filled with new Holographic dark energy and dark matter. We have derived some cosmological parameters like Deceleration parameter, EoS parameter, State-finder parameters, Cosmographic parameters, {\it Om} parameter and graphically investigated the nature of these parameters for the above mentioned interacting scenario. The results are found to be consistent with the accelerating universe. Also we have graphically investigated the trajectories in $\omega$--$\omega'$ plane for different values of the interacting parameter and explored the freezing region and thawing region in $\omega$--$\omega'$ plane. Finally, we have analyzed the stability of this model.Comment: 12 pages, 12 figures, Accepted in International Journal of Modern Physics

Study of Tachyonic Field and its statefinder diagnostics in Various Scenarios of The Anisotropic Universe

In the present work, we have considered N-dimensional Einstein field equations in which 4-dimensional space-time is described by a FRW metric and that of the extra d-dimensions by an Euclidean metric. Considering the universe filled with tachyonic field we have reconstructed the potential $V(\phi)$ corresponding to the field reconstructions in an anisotropic universe under \emph{Emergent-Power law}, \emph{Emergent-Intermediate}, \emph{Emergent-Logamediate}and \emph{Logamediate-Intermediate} scenarios. The statefinder parameters have been investigated in all of the said scenarios.Comment: 15 pages, 8 figure

Constraining Parameters of Generalized Cosmic Chaplygin Gas in Loop Quantum Cosmology

We have assumed the FRW universe in loop quantum cosmology (LQC) model filled with the dark matter and the Generalized Cosmic Chaplygin gas (GCCG) type dark energy where dark matter follows the linear equation of state. We present the Hubble parameter in terms of the observable parameters $\Omega_{m0}$ and $H_{0}$ with the redshift $z$ and the other parameters like $A$, $B$, $w_{m}$, $\omega$ and $\alpha$ which coming from our model. From Stern data set (12 points)\& SNe Type Ia 292 data (from \cite{Riess1,Riess2,Astier}) we have obtained the bounds of the arbitrary parameters by minimizing the $\chi^{2}$ test. The best-fit values of the parameters are obtained by 66\%, 90\% and 99\% confidence levels. Next due to joint analysis with Stern+BAO and Stern+BAO+CMB observations, we have also obtained the bounds of the parameters ($A,B$) by fixing some other parameters $\alpha$, $w_{m}$ and $\omega$. From the best fit values of the parameters, we have obtained the distance modulus $\mu(z)$ for our theoretical GCCG model in LQC and from Supernovae Type Ia (union2 sample 552 data from [\cite{Amanullah}] \& Riess 292 data from [\cite{Riess1,Riess2,Astier}]), we have concluded that our model is in agreement with the Supernovae Type Ia sample data. In addition, we have investigated in details about the various types of Future Singularities that may be formed in this model and it is notable that our model is completely free from any types of future singularities.Comment: 36 pages, 15 figures, Accepted in Astrophysics and Space Science (2014). arXiv admin note: substantial text overlap with arXiv:1206.0507, arXiv:1304.6713, arXiv:1406.304