Observational constraints on holographic dark energy with varying gravitational constant

TL;DR

This paper uses multiple observational datasets and MCMC methods to constrain a holographic dark energy model with a varying gravitational constant, finding it compatible with current observations and providing specific parameter estimates.

Contribution

It introduces observational constraints on a holographic dark energy model with a varying G, considering both flat and non-flat geometries, which was not extensively explored before.

Findings

Model is compatible with observations within 1σ

Estimated parameters: Ω_Λ0 ≈ 0.72, Ω_k0 ≈ -0.0013, c ≈ 0.80, Δ_G ≈ -0.0025, w_0 ≈ -1.04

Constraints support the viability of the model with current data.

Abstract

We use observational data from Type Ia Supernovae (SN), Baryon Acoustic Oscillations (BAO), Cosmic Microwave Background (CMB) and observational Hubble data (OHD), and the Markov Chain Monte Carlo (MCMC) method, to constrain the cosmological scenario of holographic dark energy with varying gravitational constant. We consider both flat and non-flat background geometry, and we present the corresponding constraints and contour-plots of the model parameters. We conclude that the scenario is compatible with observations. In 1$\sigma$ we find $\Omega_{\Lambda0}=0.72^{+0.03}_{-0.03}$, $\Omega_{k0}=-0.0013^{+0.0130}_{-0.0040}$, $c=0.80^{+0.19}_{-0.14}$ and $\Delta_G\equiv G'/G=-0.0025^{+0.0080}_{-0.0050}$, while for the present value of the dark energy equation-of-state parameter we obtain $w_0=-1.04^{+0.15}_{-0.20}$.