Primordial gravitational waves from the space-condensate inflation model

Abstract

We consider the space-condensate inflation model to study the primordial gravitational waves generated in the early Universe. We calculate the energy spectrum of gravitational waves induced by the space-condensate inflation model for the full frequency range with the assumption that the phase transition between two consecutive regimes is abrupt during the evolution of the Universe. The suppression of the energy spectrum is found in our model for the decreasing frequency of gravitational waves depending on the model parameter. To realize the suppression of the energy spectrum of the primordial gravitational waves, we study the existence of the early phase transition during inflation for the space-condensate inflation model.

Constraints on the reheating parameters after Gauss-Bonnet inflation from primordial gravitational waves

“…Refs. [16][17][18][19][20][21][22][23][24][25][26][27]. The evolution equation of the PGW for our models is given by [35]…”

“…One can attempt a task to calculate the transfer function by numerically integrating the evolution equation for the PGW following Refs. [16][17][18][19][20][21][22][23][24][25][26][27]. The evolution equation of the PGW for our models is given by [35]…”

“…The detection of the PGW background by a future observation would open up a new window in exploring the early Universe, particularly, the reheating era. It was also claimed that the temperature of reheating and the equation-of-state parameter during reheating can be probed by looking at the spectrum of the GW background [16][17][18][19][20][21][22][23][24][25][26][27]. Therefore, in this work, we consider inflationary models with a Gauss-Bonnet (GB) term to estimate the energy spectrum of the PGW and to provide constraints on the reheating parameters.…”