Inflation with two-form field: the production of primordial black holes and gravitational waves

Antisymmetric tensor field (two-form field) is a ubiquitous component in string theory and generally couples to the scalar sector through its kinetic term. In this paper, we propose a cosmological scenario that the particle production of two-form field, which is triggered by the background motion of the coupled inflaton field, occurs at the intermediate stage of inflation and generates the sizable amount of primordial black holes as dark matter after inflation. We also compute the secondary gravitational waves sourced by the curvature perturbation and show that the resultant power spectra are testable with the future space -based laser interferometers.

Automated summary

In this paper, a cosmological scenario is proposed where the particle production of two-form field is triggered by the background motion of the coupled inflaton field and generates observable amounts of primordial black holes as dark matter after inflation. The resultant power spectra of secondary gravitational waves sourced by the curvature perturbation are also computed and shown to be testable with future space-based laser interferometers.