LAUSR

In this paper, we study an interacting holographic dark energy model in the framework of fractal cosmology. The features of fractal cosmology could pass ultraviolet divergencies and also make a better understanding of the universe in different dimensions. We discuss a fractal FRW universe filled with the dark energy and cold dark matter interacting with each other. It is observed that the Hubble parameter embraces the recent observational range while the deceleration parameter demonstrates an accelerating universe and a behavior similar to ΛCDM$\Lambda \mbox{CDM}$. Plotting the equation of state shows that it lies in phantom region for interaction mode. We use Om$\mathit{Om}$-diagnostic tool and it shows a phantom behavior of dark energy which is a condition of avoiding the formation of black holes. Finally we execute the StateFinder diagnostic pair and all the trajectories for interacting and non-interacting state of the model meet the fixed point ΛCDM$\Lambda \mbox{CDM}$ at the start of the evolution. A behavior similar to Chaplygin gas also can be observed in statefinder plane. We find that new holographic dark energy model (NHDE) in fractal cosmology expressed the consistent behavior with recent observational data and can be considered as a model to avoid the formation of black holes in comparison with the main model of NHDE in the simple FRW universe. It has also been observed that for the interaction term varying with matter density, the model generates asymptotic de-Sitter solution. However, if the interaction term varies with energy density, then the model shows Big-Rip singularity. Using our modified CAMB code, we observed that the interacting model suppresses the CMB spectrum at low multipoles l<50$l<50$ and enhances the acoustic peaks. Based on the observational data sets used in this paper and using Metropolis-Hastings method of MCMC numerical calculation, it seems that the best value with 1σ$1\sigma $ and 2σ$2\sigma $ confidence interval are Ωm0=0.278−0.007−0.009+0.008+0.010$\Omega _{m0}=0.278^{+0.008~+0.010} _{-0.007~-0.009}$, H0=69.9−0.95−1.57+0.95+1.57$H_{0}=69.9^{+0.95~+1.57}_{-0.95~-1.57}$, rc=0.08−0.002−0.0027+0.02+0.027$r_{c}=0.08^{+0.02~+0.027}_{-0.002~-0.0027}$, β=0.496−0.005−0.009+0.005+0.009$\beta =0.496^{+0.005~+0.009} _{-0.005~-0.009}$, c=0.691−0.025−0.037+0.024+0.039$c= 0.691^{+0.024~+0.039}_{-0.025~-0.037}$ and b2=0.035$b^{2}=0.035$ according to which we find that the proposed model in the presence of interaction is compatible with the recent observational data.