Primordial black holes from Higgs inflation with a Gauss-Bonnet coupling

Understand

Primordial black holes (PBHs) can be the source for all or a part of today's dark matter density.

• Inflation provides a mechanism for generating the seeds of PBHs in the presence of a temporal period where the velocity of an inflaton field $\phi$ rapidly decreases toward 0.
• We compute the primordial power spectra of curvature perturbations generated during Gauss-Bonnet (GB) corrected Higgs inflation in which the inflaton field has not only a nonminimal coupling to gravity but also a GB coupling.
• For a scalar-GB coupling exhibiting a rapid change during inflation, we show that curvature perturbations are sufficiently enhanced by the appearance of an effective potential $V_{\rm eff}(\phi)$ containing the structures of plateau-type, bump-type, and their intermediate type.