Abdul Jawad

Cosmological evolution of interacting new holographic dark energy in non-flat universe

We consider the interacting holographic dark energy with new infrared cutoff (involving Hubble parameter and its derivative) in a non-flat universe. In this context, we obtain the equation of state parameter which evolutes the universe from the vacuum dark energy region towards the quintessence region for particular values of constant parameters. It is found that this model always remains unstable against small perturbations. Further, we establish the correspondence of this model having quintessential behavior with quintessence, tachyon, K-essence and dilaton scalar-field models. The dynamics of scalar fields and potentials indicate accelerated expansion of the universe, which is consistent with the current observations. Finally, we discuss the validity of the generalized second law of thermodynamics in this scenario.

Pilgrim dark energy in f( T ,T G) cosmology

We work on the reconstruction scenario of pilgrim dark energy (PDE) in f(T,TG). In PDE model it is assumed that a repulsive force that is accelerating the Universe is phantom type with (wDE<−1) and it is so strong that prevents formation of the black hole. We construct the f(T,TG) models and correspondingly evaluate equation of state parameter for various choices of scale factor. Also, we assume polynomial form of f(T,TG) in terms of cosmic time and reconstruct H and wDE in this manner. Through discussion, it is concluded that PDE shows aggressive phantom-like behavior for s=−2 in f(T,TG) gravity.

Correspondence between f(G) gravity and holographic dark energy via power-law solution

In this paper, we discuss cosmological application of holographic Dark Energy (HDE) in the framework of f(G) modified gravity. For this purpose, we construct f(G) model with the inclusion of HDE and a well-known power law form of the scale factor a(t). The reconstructed f(G) is found to satisfy a sufficient condition for a realistic modified gravity model. We find quintessence behavior of effective equation of state (EoS) parameter ωDE through energy conditions in this context. Moreover, we observe that the squared speed of sound

Analysis of generalized ghost version of pilgrim dark energy

v_{s}^{2}

Interacting modified holographic dark energy in Kaluza-Klein universe

remains negative, which indicates the instability of HDE f(G) model.

Modified holographic dark energy in non-flat Kaluza–Klein universe with varying G

The proposal of pilgrim dark energy is based on the speculation that phantom-like dark energy possesses enough resistive force to preclude the black hole formation in the later universe. We explore this phenomenon by assuming the generalized ghost version of pilgrim dark energy. We find that most of the values of the interacting (ξ2) as well as pilgrim dark energy (u) parameters push the equation of state parameter towards phantom region. The squared speed of sound shows that this model remains stable in most of the cases of ξ2 and u. We also develop

Energy contents of some well-known solutions in teleparallel gravity

omega_{varLambda}mbox{--}omega_{varLambda}

ENERGY CONTENTS OF A CLASS OF REGULAR BLACK HOLE SOLUTIONS IN TELEPARALLEL GRAVITY

plane and observe that this model corresponds to thawing as well as freezing regions. Finally, it is shown that the non-interacting and interacting generalized ghost versions of pilgrim dark energy correspond to ΛCDM limit on the statefinder plane.

Dark energy model with generalized cosmological horizon

The interaction of modified holographic dark energy and dark matter with varying G in flat Kaluza Klein universe is considered. Further, we take infrared cutoff scale L as future event horizon. In this scenario, equations of state parameter as well as evolution are explored. We also check the validity of the generalized second law of thermodynamics. It is interesting to mention here that our results show consistency with the present observations.

Analysis of pilgrim dark energy models

The purpose of this paper is to discuss the evolution of modified holographic dark energy with variable G in non-flat Kaluza–Klein universe. We consider the non-interacting and interacting scenarios of the modified holographic dark energy with dark matter and obtain the equation of state parameter through logarithmic approach. It turns out that the universe remains in different dark energy eras for both cases. Further, we study the validity of the generalized second law of thermodynamics in this scenario. We also justify that the statefinder parameters satisfy the limit of ΛCDM model.