Variable gravity: A suitable framework for quintessential inflation

Understand

In this paper, we investigate a scenario of variable gravity and apply it to the unified description of inflation and late time cosmic acceleration dubbed quintessential inflation.

• The scalar field called "cosmon" which in this model unifies both the concepts reduces to inflaton at early epochs.
• We calculate the slow-roll parameters, the Hubble parameter at the end of inflation, the reheating temperature,the tensor-to-scalar ration and demonstrate the agreement of the model with observations and the Planck data.As for the post inflationary dynamics, cosmon tracks the background before it exits the scaling regime at late times.
• The scenario gives rise to correct epoch sequence of standard cosmology, namely, radiative regime, matter phase and dark-energy.