Lagrangian formulation for an extended cosmological equation-of-state

TL;DR

This paper develops a Lagrangian formulation for an extended cosmological equation-of-state derived from the Chaplygin gas, demonstrating its viability as a dark energy model consistent with scalar field theories.

Contribution

It introduces a Lagrangian formulation for the extended equation-of-state, connecting it with scalar field models and fitting the potential with known functions.

Findings

The extended equation-of-state is compatible with dark energy observations.

A scalar field potential consistent with the model is numerically fitted.

The model bridges stellar modeling and cosmological dark energy theories.

Abstract

We show that the extended cosmological equation-of-state developed starting from a Chaplygin equation-of-state, recently applied to stellar modeling, is a viable dark energy model consistent with standard scalar potentials. Moreover we find a Lagrangian formulation based on a canonical scalar field with the appropriate self-interaction potential. Finally, we fit the scalar potential obtained numerically with concrete functions well studied in the literature. Our results may be of interest to model builders and particle physicists.