Probing a nonminimal coupling through superhorizon instability and secondary gravitational waves

Ayan Chakraborty, Subhasis Maiti, Debaprasad Maity

In this paper, we investigate the impact of scalar fluctuations ($\chi$) non-minimally coupled to gravity, $\xi {\chi }^{2}R$, as a potential source of secondary gravitational waves (SGWs). Our…