Barrow Holographic Dark Energy in non-flat Universe

TL;DR

This paper develops a model of holographic dark energy in non-flat universes, analyzing its evolution, equation-of-state, and observational consistency, revealing how spatial curvature influences dark energy behavior and fits with cosmological data.

Contribution

It extends Barrow holographic dark energy to non-flat geometries, deriving analytical equations and analyzing the impact of curvature on dark energy dynamics and observational fits.

Findings

Curvature affects the phantom regime depending on the Barrow exponent.

Positive curvature induces phantom behavior at smaller Barrow exponents.

The model aligns well with Hubble and supernova data, improving phenomenology.

Abstract

We construct Barrow holographic dark energy in the case of non-flat universe. In particular, considering closed and open spatial geometry we extract the differential equations that determine the evolution of the dark-energy density parameter, and we provide the analytical expression for the corresponding dark energy equation-of-state parameter. We show that the scenario can describe the thermal history of the universe, with the sequence of matter and dark energy epochs. Comparing to the flat case, where the phantom regime is obtained for relative large Barrow exponents, the incorporation of positive curvature leads the universe into the phantom regime for significantly smaller values. Additionally, in the case of negative curvature we find a reversed behavior, namely for increased Barrow exponent we acquire algebraically higher dark-energy equation-of-state parameters. Furthermore, we confront the scenario with Hubble parameter measurements and supernova type Ia data. Hence, the incorporation of slightly non-flat spatial geometry to Barrow holographic dark energy improves the phenomenology while keeping the new Barrow exponent to smaller values.