Holographic dark energy with the sign-changeable interaction term

Abstract

We use three IR cutoffs, including the future event horizon, the Hubble and Granda-Oliveros (GO) cutoffs, to construct three holographic models of dark energy. Additionally, we consider a Friedmann-Robertson-Walker (FRW) universe filled by a dark matter (DM) and a dark energy that interact with each other through a mutual sign-changeable interaction. Thereinafter, we address the evolution of the some cosmological parameters, such as the equation of state and dimensionless density parameters of dark energy as well as the deceleration parameter, during the cosmic evolution from the matter dominated era until the late time acceleration. We observe that a holographic dark energy (HDE) model with Hubble cutoff interacting with DM may be in line with the current universe. Our study shows that models with the future event horizon as the IR cutoff or the GO cutoff are in good agreement with the observational data. In fact, we find out that these obtained models can predict the universe transition from a deceleration phase to the acceleration one in a compatible way with observations. The three obtained models may also allow the equation of state parameter to cross the phantom line, a result which depends on the values of the system's constants such as the value of the interaction coupling constant.

Time Evolution of Density Parameters for Matter and Dark Energy and their Interaction Term in Brans-Dicke Gravity

“…Its negative value at the present time implies a decay of matter into dark energy which is responsible for the accelerated expansion of the universe. The behaviour of this interaction term is consistent with the results of some recent studies (Zadeh, Sheykhi and Moradpour 2017;Cueva and Nucamendi 2010) carried out in a completely different way. Using the expression of we have determined the time variations of ̇ and ̇ .…”

“…An effective interaction term ( ) between matter and dark energy has been calculated here and its time dependence has been studied. Its time variation is found to be consistent with the findings of some other studies (Zadeh, Sheykhi and Moradpour 2017;Cueva and Nucamendi 2010). In terms of we have determined the time rate of change of densities for matter and dark energy.…”

A generalized interacting Tsallis holographic dark energy model and its thermodynamic implications

“…Hence, the interaction between the dark sectors is indeed a more general scenario to unveil the dynamics of the universe. In fact, there are many proposed interactions in the literature to study the dynamics of the universe (for details, one can look into [65][66][67][68][69][70][71][72][73][74] and references therein), however, the exact functional form of Q is still unknown to us. From the continuity Eqs.…”

Ghost Dark Energy in the DGP Braneworld

“…In what follows we discuss the − plane which introduced by Caldwell and Linder [23] for analyzing the dynamical property of various DE models and distinguish these models ( represents the evolution of ). The models can be categorized into two different classes: (i) > 0 and < 0 which present the thawing region.…”

“…Differentiating (23) and (20) and then substituting the results in (12) we get the squared of sound speed as…”