Constraints on power spectrum of density fluctuations from PBH evaporations

TL;DR

This paper investigates how the evaporation of primordial black holes, influenced by a specific bump in the small-scale density fluctuation spectrum, constrains the characteristics of that spectrum using cosmic background data.

Contribution

It introduces a method to constrain the small-scale power spectrum of density fluctuations through neutrino and photon background observations related to primordial black hole evaporation.

Findings

Constraints on the amplitude and shape of the small-scale density fluctuation bump.

Limits on primordial black hole abundance from cosmic background data.

Implications for early universe models with enhanced small-scale fluctuations.

Abstract

We calculate neutrino and photon energy spectra in extragalactic space from evaporation of primordial black holes, assuming that the power spectrum of primordial density fluctuations has a strong bump in the region of small scales. The constraints on the parameters of this bump based on neutrino and photon cosmic background data are obtained.