Analysis of the action-based constrained adiabatic particle production model

TL;DR

This paper develops a Lagrangian formulation for gravitationally induced adiabatic particle production models, constrains their parameters, and demonstrates their ability to explain cosmic evolution from radiation era to late-time acceleration.

Contribution

It introduces a field-action formulation for particle production models and constrains their parameters based on stability and observational data.

Findings

Model explains cosmic evolution from radiation to acceleration.

Parameter range for acceleration: 1/3 < β < 2/3.

Constrained model aligns with observational data.

Abstract

The theory of gravitationally induced adiabatic particle production offers an alternative approach to exploring the accelerating expansion of the universe. However, existing models generally lack a well-defined field-action formulation. This article aims to establish a suitable Lagrangian formulation consistent with the framework of particle creation. A general form of action is considered for this purpose. The corresponding field equations in comparison with those commonly used in the particle creation formalism leads to some specific form of the Lagrangian, which further constrains the form of the particle creation models. We perform the phase space stability analysis of the constrained model and compared with observational data. Our result shows that the constrained model is capable of explaining the cosmic evolution from the radiation to the late-time cosmic acceleration if the model parameter lies within the range $1/3 < \beta < 2/3$.