Cosmographic study of the universe's specific heat: A landscape for Cosmology?

TL;DR

This paper introduces a thermodynamic approach to cosmology by defining the universe's specific heat using cosmography, revealing compatibility with observations and proposing a model that addresses key issues in standard cosmology.

Contribution

It presents a novel method to compute the universe's specific heat from cosmography, linking thermodynamics with observational data and proposing a model that resolves fine-tuning and coincidence problems.

Findings

Negative specific heat at constant volume compatible with data

Zero specific heat at constant pressure compatible with data

Proposed cosmological model overcomes fine-tuning and coincidence problems

Abstract

We propose a method for constructing the specific heat for the universe by following standard definitions of classical thermodynamics, in a spatially flat homogeneous and isotropic spacetime. We use cosmography to represent the specific heat in terms of measurable quantities, and show that a negative specific heat at constant volume and a zero specific heat at constant pressure are compatible with observational data. We derive the most general cosmological model which is compatible with the values obtained for the specific heat of the universe, and show that it overcomes the fine-tuning and the coincidence problems of the $\Lambda$CDM model.