Primordial black holes and scalar induced gravitational waves from the $E$ model with a Gauss-Bonnet term

Understand

We study an inflationary $E$ model with the Gauss-Bonnet coupling, which can enhance the curvature perturbation at small scales and thus produce a significant abundance of primordial black holes (PBHs) and detectable scalar induced gravitational waves (SIGWs).

• PBHs from the $E$ model with mass $30M_{\odot}$, $10^{-5}M_{\odot}$, and $10^{-12}M_{\odot}$ can explain the LIGO-Virgo events, the ultrashort-timescale microlensing events in the OGLE data, and all dark matter, respectively.
• SIGWs produced by the $E$ model can account for the recent NANOGrav signal.
• We also compute the primordial non-Gaussianity and discuss its impact on PBHs and SIGWs.