arXiv subjects

A. Asvar

Publications and source records attributed to A. Asvar.

2 recordsLinked to original sources

arXiv2026

Kaniadakis Holographic Dark Energy with Particle Horizon as IR Cutoff

We construct a holographic dark-energy model using Kaniadakis entropy with the particle horizon as the infrared cutoff, consistently modifying both the holographic density and the Friedmann background. In standard Einstein gravity, noninteracting particle-horizon holographic dark energy (HDE) does not produce the sufficiently negative pressure required for late-time accelerated expansion. We show that the Kaniadakis deformation changes this behavior while the particle horizon is retained. For the representative parameter choice $K=1.90\times10^{-36}$, with $\Omega_{\rm DE0}=0.7$ and $c^2=0.64$, the deceleration parameter changes sign at $z\simeq0.585$ in the noninteracting case. Including the interaction strengths $b^2=0.03$ and $0.06$ changes the transition only slightly, giving $z\simeq0.586$ and $0.589$, respectively. Thus, for the parameter set considered here, the interaction does not generate the acceleration; rather, the transition is already present in the noninteracting Kaniadakis model and the interaction produces only a small shift in its timing. We derive the autonomous evolution equations, the effective dark-energy equation of state, and the deceleration parameter. The adiabatic squared sound speed is also examined as a diagnostic of the effective-fluid stability, while statefinder variables are used to characterize deviations from $\Lambda$CDM. Finally, we verify that the $K\to0$ limit continuously recovers standard Einstein-gravity particle-horizon HDE, for which the noninteracting model remains decelerating.

gr-qc↗

arXiv2025

Holographic dark energy in modified Kaniadakis cosmology

It is well-known that any modification to the entropy expression not only change the energy density of the holographic dark energy, but also modifies the cosmological field equations through thermodynamics-gravity correspondence. Here we propose a Kaniadakis holographic dark energy (KHDE) in the background of the modified Kaniadakis cosmology by incorporating the effects of Kaniadakis entropy into the Friedmann equations. We choose the Hubble radius, $L=H^{-1}$, as system's IR cutoff and determine the cosmological implications of this model. We first consider a dark energy (DE) dominated universe and reveal that this model mimics the cosmological constant with $w_{DE}=-1$. This implies that the theoretical origin of the cosmological constant, $\Lambda$, may be understood through KHDE in the context of Kaniadakis cosmology. Remarkably, we observe that in the absence of interaction between DE and dark matter (DM), and in contrast to HDE in standard cosmology, our model can explain the current acceleration of the cosmic expansion for the Hubble radius as IR cutoff. When the interaction between DE and DM is taken into account, we see that the total equation of state parameter (EoS), $w_{tot}=p_{tot}/\rho_{tot}$ can cross the phantom line at the present time. We also analyze the squared speed of sound, $v_s^2$, for this model and find out that $(v_s^2<0)$ for interacting KHDE. Investigating the statefinder, confirms the distinction between KHDE and $\Lambda$CDM model. It is seen that the statefinder diagram move away from the point of $\left\lbrace r,s\right\rbrace= \left\lbrace 1,0\right\rbrace$ with increasing the interaction parameter.

gr-qc↗