Cosmological dinosaurs

TL;DR

This paper explores the hypothesis that primordial black holes with masses over a million solar masses formed early in the universe, potentially explaining peculiarities in distant galaxies and quasars, and affecting early chemical composition.

Contribution

It presents calculations of black hole growth in protogalaxies and discusses the implications of primordial black holes on early universe chemistry and exotic star formation.

Findings

Standard models cannot achieve sufficient black hole growth without complex assumptions.

Primordial black holes could significantly alter chemical compositions during nucleosynthesis.

Potential to study extremal matter and field evolution if such black holes exist.

Abstract

The hypothesis of existence of primordial black holes with large masses (\geq 10^6 M\odot), formed at the earliest stages of the Universe evolution, is considered in the paper. The possibility does not contradict some theories, see e.g. Barkana & Loeb (2001), and may match new observational data. In particular, this scenario of evolution could describe some peculiarities in distant galaxies and quasars. Calculations of evolution of central body mass in protogalaxies for different initial conditions are presented. It is shown that the sufficient rate of BH mass growth is not achieved in the standard scheme without complex additional assumptions. Moreover, the appearance of a primordial black hole in the epoch of primordial nucleosynthesis could significantly change the chemical composition around it. This can lead to different exotic stars with low mass and nonstandart metals enrichment. The proposed scheme is not considered as universal. On the other hand, if only tiny part of existed objects have the considered nature, it gives a unique possibility to study extremal stages of matter and fields evolution in our Universe.