Tsallis Holographic Dark Energy Model Research Articles

Tsallis holographic dark energy in Bianchi type-III spacetime with scalar fields

In this paper, we study one of the new dark energy models named Tsallis holographic dark energy (THDE) model considering the Bianchi type-III spacetime model. Considering deceleration parameter, transition from deceleration to acceleration phase happens at [Formula: see text]. The equation of state (EoS) parameter has been found using the Granda–Oliveros (GO) scale. It is found that for [Formula: see text] values, EoS parameter behaves like the quintessence era; for [Formula: see text], EoS parameter behaves like the phantom dark energy and approaches [Formula: see text]CDM model at late-time cosmic acceleration phase. Also, we reconstructed a correspondence between THDE model and some well-known scalar fields, such as tachyon, quintessence and [Formula: see text]-essence. In addition, we evaluated equation of state parameter, kinetic energy and scalar potential versus time.

Tsallis holographic model of dark energy: Cosmic behavior, statefinder analysis and ωD–ωD′ pair in the nonflat universe

This paper investigates the Tsallis holographic dark energy (THDE) model in accordance with the apparent horizon as an infrared cut-off, in a non flat universe. The cosmological evolution of the deceleration parameter and equation of state of THDE model are calculated. The evolutionary trajectories are plotted for the THDE model for distinct values of the Tsallis parameter [Formula: see text] besides distinct spatial curvature contributions, in the statefinder [Formula: see text] parameter-pairs and [Formula: see text] plane, considering the present value of dark energy (DE) density parameter [Formula: see text], [Formula: see text], in the light of [Formula: see text] observational data. The statefinder and [Formula: see text] plane plots specify the feature of the THDE and demonstrate the separation between this framework and other models of DE.

Observational constraints on interacting Tsallis holographic dark energy model

In this paper, we investigate a recent proposed model – so called the Tsallis holographic dark energy (THDE) model with consideration of the Hubble and the event future horizon as IR cutoffs. In this case, we consider the non-gravitational and phenomenological interaction between dark sectors. We fit the free parameters of the model using Pantheon Supernovae Type Ia data, Baryon Acoustic Oscillations, Cosmic Microwave Background, Gamma-Ray burst and the the local value of the Hubble constant. We examine the THDE model to check its compatibility with observational data using objective Information Criterion (IC). We find that the THDE models cannot be supported by observational data once the Lambda CDM is considered as the referring model. Therefore we re-examine the analysis with the standard holographic dark energy model (HDE) as another reference. Changing the Lambda CDM to main standard dark energy model (HDE), we observe the compatibility of the THDE models. Using the Alcock–Paczynski (AP) test we check the deviation of the model compared to Lambda CDM and HDE. Surveying the evolution of squared of sound speed v^2_s as an another test we check the stability of the interacting and non-interacting THDE models and we find that while the THDE model with the Hubble horizon as IR cutoff is unstable against the background perturbation, the future event horizon as IR cutoff show stability at the late time. In addition, using the modified version of the CAMB package, we observe the suppressing the CMB spectrum at small K-modes and large scale.

Stability analysis of a Tsallis holographic dark energy model

Using the generalized Tsallis entropy, the Tsallis holographic dark energy(THDE) was proposed recently. In this paper we analyze the cosmological consequences of the THDE model with an interaction between dark energy and dark matter . We find that the THDE model can explain the current accelerated cosmic expansion, and it is stable under certain conditions. Furthermore, through investigating the dynamical analysis, we find that there exists an attractor which represents an accelerated expansion phase of the universe. When , this attractor corresponds to a dark energy dominated de Sitter solution and the universe can evolve into an era which is depicted by the CDM model. The age of universe in this model is also explored.

Tsallis holographic dark energy in FRW universe with time varying deceleration parameter

By considering the time-varying deceleration parameter (DP), we have investigated Tsallis holographic dark energy (THDE), infrared cut-off with the Hubble horizon proposed by Tavayef, et al. (2018) in the framework of Friedmann Robertson Walker universe. The proposed THDE model describes that the universe is in an accelerating expansion mode. Interestingly enough, the EoS parameter in our model is representing the outstanding evolution of the universe as, the quintessence era (ωT≥−1), phantom era (ωT<−1), according to the value of dimensionless parameter δ. To analyze the different structure of the model, we try to accommodate the two perspectives of (DE) by reconstructing the scalar field potential, which depicts the accelerated expansion at present. We examine the validity of the model by drawing the statefinder parameters and comparing them with the recent observational outcomes of cosmography.

Study of F(T) gravity in the framework of the Tsallis holographic dark energy model

In the present study, a new f(T) modified gravity model is established using a Tsallis holographic dark energy model (THDE) with a Hubble cutoff. Assuming a power law scale factor we verified the growth of dark energy; deceleration parameter q is considered, which shows that the universe is in acceleration mode. Moreover, in order to study the stability of our model, we consider the square of speed of sound $v_{D}^{2}$ , showing that the model is stable over the considered range of redshift z. We illustrate the evolution of energy conditions, and we notice that the strong energy condition (SEC) and the weak energy condition (WEC) are violated over the accelerated phantom regime.

Diagnosing Tsallis holographic dark energy models with statefinder and ω − ω′ pair

A useful method, known as statefinder diagnostic, which may differentiate one dark energy (DE) model from others is applied in this work to a holographic dark energy (HDE) model from Tsallis entropy, called the Tsallis holographic dark energy (THDE) model. The evolutionary trajectories of this model are plotted in the statefinder parameter — planes and [Formula: see text] plane, and it is observed that the parameter [Formula: see text] of this model plays a magnificent role from the statefinder and [Formula: see text] plane viewpoints. Eventually, the evolutionary trajectories are plotted considering two different values of THDE energy density ([Formula: see text]), [Formula: see text], in the light of Planck 2018 results VI base-LCDM cosmology and [Formula: see text], in the light of SNe + BAO + OHD + CMB observation data.

Non-flat FRW universe version of Tsallis holographic dark energy in specific modified gravity

Among various dark energy models, Tsallis holographic dark energy model shows the dynamical enthusiasm to describe the transition phase of the universe. In this paper, we consider Tsallis holographic dark energy with event and apparent horizon as an infrared cutoff in the framework of dynamical Chern–Simon modified gravity and non-flat FRW universe. We explore Hubble, equation of state and deceleration parameters and found that Hubble parameter lies in the range [Formula: see text] and [Formula: see text] for event and apparent horizon trajectories, respectively. It is mentioned here that the equation of state parameter lies within the range [Formula: see text] (event) and [Formula: see text] (apparent). Also, deceleration parameter for both cases show accelerated and decelerated phase of universe as well as cosmological constant. Moreover, we also checked the stability of our model through square speed of sound, which shows the positive behavior (exhibits the stability of the model). Finally, we observe that the generalized second law of thermodynamics remains valid in both cases of horizon.

Statefinder diagnosis for interacting Tsallis holographic dark energy models with [formula omitted] pair

A new model of dark energy, named as Tsallis holographic dark energy (THDE), infrared cut-off with the Hubble horizon has been proposed by Tavayef (2018). Then, in arXiv:1806.07285, it has been expanded considering the interaction between THDE and pressure less dark matter. In this work, we explore the THDE model admitting the mutual interaction between dark matter and dark energy, from the statefinder perspective. In the statefinder parameters-diagram, the evolutionary trajectories of the interacting THDE have been plotted for different cases of interaction and also for different intervals of the Tsallis non-additive parameter δ. The discrimination of the interacting and non-interacting. THDE model is described by the state finder analysis. Subsequently, the statefinder graph shows the effect of the interaction on the universe evolution. In addition, we examined the THDE model with interaction as a supplement to the statefinder analysis in the ω′−ω plane, which may furnish us with a dynamic analysis.

Tsallis Holographic Dark Energy in f(G,T) Gravity

In this paper, we study the reconstruction paradigm for Tsallis holographic dark energy model using generalized Tsallis entropy conjecture with Hubble horizon in the framework of f ( G , T ) gravity (G and T represent the Gauss-Bonnet invariant and trace of the energy-momentum tensor). We take the flat Friedmann-Robertson-Walker universe model with dust fluid configuration. The cosmological evolution of reconstructed models is examined through cosmic diagnostic parameters and phase planes. The equation of the state parameter indicates phantom phase while the deceleration parameter demonstrates accelerated cosmic epoch for both conserved as well as non-conserved energy-momentum tensor. The squared speed of the sound parameter shows instability of the conserved model while stable non-conserved model for the entire cosmic evolutionary paradigm. The trajectories of the ω G T − ω G T ′ plane correspond to freezing as well as thawing regimes for the conserved and non-conserved scenario, respectively. The r − s plane gives phantom and quintessence dark energy epochs for conserved while Chaplygin gas model regime for the non-conserved case. We conclude that, upon the appropriate choice of the free parameters involved, the derived models demonstrate a self-consistent phantom universe behavior.

Tsallis Holographic Dark Energy with Granda-Oliveros Scale in (n+1)-Dimensional FRW Universe

Based on Tsallis holographic dark energy model recently proposed by using the general model of the Tsallis entropy expression, we reconstruct cosmographic parameters, q,j,κ,l, and we study their evolution in spatially flat (n+1)-dimensional Friedmann-Robertson-Walker universe using Granda-Oliveros scale. Our results show that the universe is in an accelerating expansion mode described by phantom-like behavior. We go further and study the state finder operators and the Om diagnostic to understand the behavior of our model. The stability of the system is also studied by using the square of speed of sound showing that our model is stable over the low range of red-shift considered. The results indicate that the entropy formalism will play an important role in understanding the dynamics of our universe.

Note on Tsallis holographic dark energy

We explore the effects of considering various infrared (IR) cutoffs, including the particle horizon, the Ricci horizon and the Granda–Oliveros (GO) cutoffs, on the properties of Tsallis holographic dark energy (THDE) model, proposed inspired by Tsallis generalized entropy formalism (Tavayef et al. in Phys Lett B 781:195, 2018). Interestingly enough, we find that for the particle horizon as IR cutoff, the obtained THDE model can describe the late time accelerated universe. This is in contrast to the usual HDE model which cannot lead to an accelerated universe, if one considers the particle horizon as the IR cutoff. We also investigate the cosmological consequences of THDE under the assumption of a mutual interaction between the dark sectors of the Universe. It is shown that the evolution history of the Universe can be described by these IR cutoffs and thus the current cosmic acceleration can also be realized. The sound instability of the THDE models for each cutoff are also explored, separately.