An effective model for inflation from geometrothermodynamics: a detailed analysis of thermodynamics and cosmological perturbations

TL;DR

This paper proposes a thermodynamic inflation model based on geometrothermodynamics, using a van der Waals-like equation to describe the universe's early rapid expansion, aligning with cosmological observations.

Contribution

It introduces a novel inflationary model derived from geometrothermodynamics with a specific fundamental equation, providing a thermodynamic perspective on cosmic inflation.

Findings

Model predicts the correct number of e-foldings.

Phase transition behavior aligns with inflationary requirements.

Cosmological perturbations match observed primordial power spectrum.

Abstract

Inflationary models usually assume the existence of scalar fields or other exotic gravitational sources. We investigate an alternative approach in which the entire Universe is considered as a thermodynamic system described by geometrothermodynamics. A particular van der Waals like fundamental equation is used to construct an effective inflationary model which is consistent with the main physical requirements, such as the number of e-foldings and the times for the onset and end of inflation, predicting in this way a volume of approximately $10^{-84}$ m$^3$ at the onset of inflation. The phase transition structure and thermodynamic behavior of the system are consistent with the expected properties of an inflationary scenario. Cosmological perturbations of the model are shown to be in agreement with the corresponding primordial power spectrum providing the seeds for the creation of large-scale structure.