Cosmological constraints on primordial black holes produced in the near-critical gravitational collapse

TL;DR

This paper calculates the mass distribution of primordial black holes formed via near-critical gravitational collapse and compares it with cosmological constraints, identifying new excluded mass ranges.

Contribution

It provides a nearly distribution-independent calculation of primordial black hole mass functions assuming a peaked density fluctuation spectrum.

Findings

Identifies new excluded mass ranges for primordial black holes.

Provides a robust method for mass function calculation independent of fluctuation distribution.

Constrains the volume fraction of collapsing regions as a function of horizon mass.

Abstract

The mass function of primordial black holes created through the near-critical gravitational collapse is calculated in a manner fairly independent of the statistical distribution of underlying density fluctuation, assuming that it has a sharp peak on a specific scale. Comparing it with various cosmological constraints on their mass spectrum, some newly excluded range is found in the volume fraction of the region collapsing into black holes as a function of the horizon mass.