Different Faces of Generalized Holographic Dark Energy

Abstract

In the formalism of generalized holographic dark energy (HDE), the holographic cut-off is generalized to depend upon LIR=LIRLp,L˙p,L¨p,⋯,Lf,L˙f,⋯,a with Lp and Lf being the particle horizon and the future horizon, respectively (moreover, a is the scale factor of the Universe). Based on such formalism, in the present paper, we show that a wide class of dark energy (DE) models can be regarded as different candidates for the generalized HDE family, with respective cut-offs. This can be thought as a symmetry between the generalized HDE and different DE models. In this regard, we considered several entropic dark energy models—such as the Tsallis entropic DE, the Rényi entropic DE, and the Sharma–Mittal entropic DE—and found that they are indeed equivalent with the generalized HDE. Such equivalence between the entropic DE and the generalized HDE is extended to the scenario where the respective exponents of the entropy functions are allowed to vary with the expansion of the Universe. Besides the entropic DE models, the correspondence with the generalized HDE was also established for the quintessence and for the Ricci DE model. In all the above cases, the effective equation of state (EoS) parameter corresponding to the holographic energy density was determined, by which the equivalence of various DE models with the respective generalized HDE models was further confirmed. The equivalent holographic cut-offs were determined by two ways: (1) in terms of the particle horizon and its derivatives, (2) in terms of the future horizon horizon and its derivatives.

Rényi Holographic Dark Energy Models In Multidimensional Universe

“…(25). Thus we conclude that in higher dimensions also, Ω R HDE is equivalent to w D as obtained in [35] for four dimensions.…”

“…Cosmology itself does not offer any unique choice of the long-distance cutoff, also known as the infrared cut off (IR cut off) for any of the HDE models [33]. One of the most natural choices of IR cut off is the Hubble horizon (for cosmology in generaliged HDE and with arbitrarty cut off see [34,35]). However, in the original model of HDE (OHDE) if one considers the Hubble radius as IR cut off and the Bekenstein entropy, then both dark matter (DM) and OHDE are scaled with the same function of the scale factor.…”

Holographic dark energy in Gauss-Bonnet gravity with Granda-Oliveros cut-off

“…( 19), the holographic dark energy density is proportional to the squared infrared cut-off L IR . The IR cut-off is supposed to be the particle horizon L P or the future event horizon L F , which are determined respectively as [55] L…”

The Sharma–Mittal Model’s Implications on FRW Universe in Chern–Simons Gravity

“…Sharma and Dubey [29] explored the SMHDE models with different diagnostic tools. Nojiri with fellows [30] studied Sharma-Mittal entropic DE and showed that it is indeed equivalent with the generalized HDE.…”