PBH Dark Matter in Supergravity Inflation Models

TL;DR

This paper presents a supergravity-based double inflation model that generates primordial black holes by leveraging a flat inflection point in the potential, with implications for dark matter.

Contribution

It introduces a novel supergravity inflation scenario with a second phase producing small-scale perturbations leading to PBH formation, incorporating linear, quadratic, and cubic potential terms.

Findings

Primordial black holes can be abundantly produced in this model.

The model aligns with the cosmological constant and flatness conditions.

PBH production is linked to the inflection point in the inflation potential.

Abstract

We propose a novel scenario to produce abundant primordial black holes (PBHs) in new inflation which is a second phase of a double inflation in the supergravity frame work. In our model, some preinflation phase before the new inflation is assumed and it would be responsible for the primordial curvature perturbations on the cosmic microwave background scale, while the new inflation produces only the small scale perturbations. Our new inflation model has linear, quadratic, and cubic terms in its potential and PBH production corresponds with its flat inflection point. The linear term can be interpreted to come from a supersymmetry-breaking sector, and with this assumption, the vanishing cosmological constant condition after inflation and the flatness condition for the inflection point can be consistently satisfied.