We consider the framework of quintessential inflation in the warm background which is caused by the dissipation of the scalar field energy density into relativistic degrees of freedom. The dissipation process has important consequences for the evolution both at the levels of background as well as perturbation and allows us to easily satisfy the observational constraints. Our numerical analysis confirms that the model conforms to observational constraints even if the field-radiation coupling strength is weak. In the warm background, we investigate the postinflationary evolution of relic gravity waves produced during inflation whose amplitude is constrained by the big bang nucleosynthesis constraint. Further, we investigate the effect of coupling on the amplitude of gravity waves and obtain the allowed phase space between the model parameters. The mechanism of quintessential inflation gives rise to blue spectrum of gravitational wave background at high frequencies. We discuss the perspectives of detection of the signal of relic gravity waves by future proposed missions. Improvements of their sensitivities in the high frequency regime, in future, might allow us to probe the blue tilt of the spectrum caused by the presence of kinetic regime in the underlying framework of inflation.

• Received 26 November 2020
• Accepted 5 January 2021

DOI:https://doi.org/10.1103/PhysRevD.103.043505