Universe acceleration and fine structure constant variation in BSBM theory

TL;DR

This paper explores how BSBM theory, involving a scalar field, can explain universe acceleration and variations in the fine structure constant, using observational data to constrain the model.

Contribution

It introduces a detailed analysis of BSBM theory with an exponential potential, testing its predictions against observational data and analyzing stability and phase space.

Findings

Model fits observational data well

Predicts variation in fine structure constant

Forecasts recent universe acceleration and phantom crossing

Abstract

In this work we investigate the utility of using SNe Ia observations in constraining the cosmological parameters in BSBM theory where a scalar field is responsible for both fine structure constant variation and late time universe acceleration. The model is discussed in the presence of an exponential self potential for the scalar field. Stability and phase space analysis of the solutions are studied. The model is tested against observational data for Hubble parameter and quasar absorption spectra. With the best fitted model parameters, the theory predicts a good match with the experimental results and exhibits fine structure constant variation. The analysis also shows that for the equation of state parameter, recent universe acceleration and possible phantom crossing in future is forecasted.