Primordial Black Holes as All Dark Matter

TL;DR

This paper proposes primordial black holes as the sole dark matter candidate, demonstrating their production in a specific inflation model and exploring their mass ranges and cosmological implications.

Contribution

It introduces a smooth-hybrid inflation model that naturally produces primordial black holes with specific masses suitable as dark matter.

Findings

Primordial black holes can account for all dark matter within certain mass ranges.

The model predicts sharply-defined black hole masses at the end of inflation.

Effects on the scalar spectral index are analyzed in relation to black hole formation.

Abstract

We argue that a primordial black hole is a natural and unique candidate for all dark matter. We show that, in a smooth-hybrid new double inflation model, a right amount of the primordial black holes, with a sharply-defined mass, can be produced at the end of the smooth-hybrid regime, through preheating. We first consider masses < 10^(-7)M_sun which are allowed by all the previous constraints. We next discuss much heavier mass 10^5 M_sun hinted at by entropy, and galactic size evolution, arguments. Effects on the running of the scalar spectral index are computed.