Holographic dark energy from nonadditive entropy: cosmological perturbations and observational constraints

Understand

We apply the holographic principle in the cosmological context through the nonadditive Tsallis entropy, used to describe the thermodynamic properties of nonstandard statistical systems such as the gravitational ones.

• Assuming the future event horizon as the infrared cutoff, we build a dark energy model free from cosmological inconsistencies, which includes standard thermodynamics and standard holographic dark energy as a limiting case.
• We thus describe the dynamics of Tsallis holographic dark energy in a flat FLRW background.
• Hence, we investigate cosmological perturbations in the linear regime on sub-horizon scales.