Teleparallel Gravity and Quintessence: The Role of Nonminimal Boundary Couplings

TL;DR

This paper develops a dynamical system approach within scalar-tensor gravity with nonminimal boundary couplings, analyzing cosmological models and their compatibility with observations, highlighting late-time acceleration and stability of solutions.

Contribution

It introduces a novel dynamical system framework for scalar-tensor gravity with boundary couplings, constrains models with observational data, and compares results with the standard b1b5b4b1bcb4 model.

Findings

Identifies stable dark energy-dominated critical points.

Models compatible with Supernovae Ia and H(z) data.

Demonstrates late-time cosmic acceleration in the framework.

Abstract

In this paper, we have outlined the development of an autonomous dynamical system within a general scalar-tensor gravity framework. This framework encompasses the overall structure of the non-minimally coupled scalar field functions for both the torsion scalar ($T$) and the boundary term ($B$). We have examined three well-motivated forms of potential functions and constrained the model parameters through dynamical system analysis. This analysis has played a crucial role in identifying cosmologically viable models. We have analysed the behaviour of dynamical parameters such as equation-of-state parameters for dark energy and the total, as well as all the standard density parameters for radiation, matter, and dark energy to assess their compatibility with current observational data. The phase space diagrams are presented to support the stability conditions of the corresponding critical points. The Universe is apparent in its late-time cosmic acceleration phase via the dark energy-dominated critical points. Additionally, we compare our findings with the most prevailing $\Lambda$CDM model. The outcomes are further inspected using the cosmological data sets of Supernovae Ia and the Hubble rate H(z).