Holographic dark energy interacting with two fluids and validity of generalized second law of thermodynamics

Abstract

We have considered a cosmological model of holographic dark energy interacting with dark matter and another unknown component of dark energy of the universe. We have assumed two interaction terms Q and Q ′ in order to include the scenario in which the mutual interaction between the two principal components (i.e., holographic dark energy and dark matter) of the universe leads to some loss in other forms of cosmic constituents. Our model is valid for any sign of Q and Q ′ . If Q < Q ′ , then part of the dark energy density decays into dark matter and the rest in the other unknown energy density component. But if Q > Q ′ , then dark matter energy receives from dark energy and from the unknown component of dark energy. Observation suggests that dark energy decays into dark matter. Here we have presented a general prescription of a cosmological model of dark energy which imposes mutual interaction between holographic dark energy, dark matter and another fluid. We have obtained the equation of state for the holographic dark energy density which is interacting with dark matter and other unknown component of dark energy. Using first law of thermodynamics, we have obtained the entropies for holographic dark energy, dark matter and other component of dark energy, when holographic dark energy interacting with two fluids (i.e., dark matter and other component of dark energy). Also we have found the entropy at the horizon when the radius (L) of the event horizon measured on the sphere of the horizon. We have investigated the GSL of thermodynamics at the present time for the universe enveloped by this horizon. Finally, it has been obtained validity of GSL which implies some bounds on deceleration parameter q.

Thermodynamics of interacting holographic dark energy

“…No interaction or variable EoS could have change that result. This result coincides with the work of authors in [24] for their chosen Ansatz and it was briefly mentioned at the end of [31]. Now, we consider a linear combination of the Hubble horizon L H and the Event Horizon L E assumed by [10], while investigating thermodynamics and the phantom barrier.…”

“…In [23] the authors study GSL for interacting dark energy in a non-flat FRW universe enclosed by the dynamical apparent horizon, and expressing the total change in entropy as a function of variables estimated today they conclude that the GSL is respected for the present time. Later on, the author in [24] generalizes this to three fluids for an event horizon and concludes that the GSL is not respected for the present time. In [25] the authors test thermodynamical laws considering a total energy density to obtain the change in entropy and then using three variable EoS of HDE.…”

Accelerated and decelerated expansion in a causal dissipative cosmology

“…Also in Ref. [41] was established that for a quintessence dominated era the generalized second law of thermodynamics (dS/dt > 0) can not be satisfied under the holographic scheme.…”

Analysis of Bianchi Type V Holographic Dark Energy Models in General Relativity and Lyra’s Geometry

“…Granda and Oliveros [8] have also studied the correspondence between the quintessence, tachyon, k-essence, and dilation dark energy models with this holographic dark energy model in the flat FRW universe. Chattopadhyay and Debnath [9], Farajollahi et al [10], Debnath [11], Malekjani [12], and Sarkar [13,14] are some of the researchers who have investigated several aspects of holographic dark energy. Recently, Kiran et al [15,16] have studied minimally interacting dark energy models in some scalar-tensor theories.…”