Thermodynamically consistent entropic-force cosmology

TL;DR

This paper investigates the thermodynamical consistency of entropic-force cosmological models, exploring generalized entropy forms and their implications for universe temperature and observational data fitting.

Contribution

It introduces a framework for analyzing entropic-force cosmology with arbitrary entropy scaling, ensuring thermodynamic consistency and comparing models with supernovae data.

Findings

Temperature of the universe horizon differs from Hawking temperature.

Generalized entropies can be constrained by supernovae data.

Thermodynamically consistent models fit observational data effectively.

Abstract

We analyze the thermodynamical consistency of entropic-force cosmological models. Our analysis is based on a generalized entropy scaling with an arbitrary power of the Hubble radius. The Bekenstein-Hawking entropy, proportional to the area, and the nonadditive $S_{\delta=3/2}$-entropy, proportional to the volume, are particular cases. One of the points to be solved by entropic-force cosmology for being taken as a serious alternative to mainstream cosmology is to provide a physical principle that points out what entropy and temperature have to be used. We determine the temperature of the universe horizon by requiring that the Legendre structure of thermodynamics is preserved. We compare the performance of thermodynamically consistent entropic-force models with regard to the available supernovae data by providing appropriate constraints for optimizing alternative entropies and temperatures of the Hubble screen. Our results point out that the temperature differs from the Hawking one.