Production of gravitational waves during preheating with nonminimal coupling

摘要

We study the preheating and the in-process production of gravitational waves(GWs) after inflation in which the inflaton is nonminimally coupled to thecurvature in a self-interacting quartic potential with the method of latticesimulation. We find that the nonminimal coupling enhances the amplitude of thedensity spectrum of inflaton quanta, and as a result, the peak value of the GWspectrum generated during preheating is enhanced as well and can reach thelimit of detection in future GW experiments. The peaks of the GW spectrum notonly exhibit distinctive characteristics as compared to those of minimallycoupled inflaton potentials but also imprint information on the nonminimalcoupling and the parametric resonance, and thus the detection of these peaks inthe future will provide us a new avenue to reveal the physics of the earlyuniverse.