Study of non-canonical scalar field model using various parametrizations of dark energy equation of state

TL;DR

This paper explores non-canonical scalar field cosmological models with various dark energy equations of state, analyzing their evolution and compatibility with observational data, revealing different future behaviors including a model mimicking Lambda-CDM.

Contribution

It introduces four parametrizations of the dark energy equation of state within a non-canonical scalar field framework and analyzes their cosmological implications and observational consistency.

Findings

Deceleration parameter transitions from positive to negative, indicating universe's transition from deceleration to acceleration.

One model (GCG) closely resembles Lambda-CDM in the future.

Two models (CPL and JBP) predict future singularities.

Abstract

In this present work, we try to build up a cosmological model using a non-canonical scalar field within the framework of a spatially flat FRW space-time. In this context, we have considered four different parametrizations of the equation of state parameter of the non-canonical scalar field. Under this scenario, analytical solutions for various cosmological parameters have been found out. It has been found that the deceleration parameter shows a smooth transition from a positive value to some negative value which indicates that the universe was undergoing an early deceleration followed by late time acceleration which is essential for the structure formation of the universe. With these four parametrizations, the future evolution of the models are also discussed. It has been found that one of the models (Generalized Chaplygin gas model, GCG) mimics the concordance $\Lambda$CDM in the near future, whereas two other models (CPL and JBP) diverge due to future singularity. Finally, we have studied these theoretical models with the latest datasets from SN Ia $+$ $H(z)$ $+$ BAO/CMB.