Thermodynamically consistent entropic late-time cosmological acceleration

TL;DR

This paper investigates entropic-force cosmological models with a generalized entropy scaling, demonstrating that including a power-law correction term can account for multiple acceleration and deceleration phases in the universe's late-time evolution.

Contribution

It introduces a thermodynamically consistent entropic-force model with arbitrary entropy scaling, enabling analysis of various behaviors and fitting to observational data.

Findings

The correction term can explain multiple acceleration and deceleration periods.

Models with arbitrary entropy scaling can be constrained by supernovae data.

The approach provides insights into the form of cosmological entropy and temperature.

Abstract

Entropic-force cosmology provides, in contrast with dark energy descriptions, a concrete physical understanding of the accelerated expansion of the universe. The acceleration appears to be a consequence of the entropy associated with the information storage in the universe. Since these cosmological models are unable of explaining the different periods of acceleration and deceleration unless a correction term is considered, we study the effects of including a subdominant power-law term within a thermodynamically admissible entropic-force model. The temperature of the universe horizon is obtained by a clear physical principle, i.e., requiring that the Legendre structure of thermodynamics is preserved. We analyze the various types of behaviors, and we compare the performance of thermodynamically consistent entropic-force models with regard to available supernovae data by providing appropriate constraints for optimizing alternative entropies and temperatures of the Hubble screen. The novelty of our work is that the analysis is based on a entropy scaling with an arbitrary power of the Hubble radius, instead of a specific entropy. This allows us to conclude on various models at once, compare them, and conserve the scaling exponent as a parameter to be fitted with observational data, thus providing information about the form of the actual cosmological entropy and temperature. We show that the introduced correction term is capable of explaining different periods of acceleration and deceleration in the late-time universe.