# PBH remnants as dark matter produced in thermal, matter and runaway-quintessence post-inflationary scenarios

## TL;DR

This paper explores how primordial black hole remnants formed in various inflationary scenarios could account for dark matter, with models consistent with Planck data and implications for early universe reheating.

## Contribution

It introduces inflationary models within $eta$-attractors that produce PBH remnants as dark matter, linking early universe dynamics with current cosmological observations.

## Key findings

- PBH remnants can constitute all dark matter over a wide mass range.
- Inflationary models produce PBHs during matter, radiation, and kination eras.
- Runaway inflaton models naturally reheat the universe and generate entropy.

## Abstract

We investigate the cosmology of mini Primordial Black Holes (PBHs) produced by large density perturbations. The mini PBHs evaporate promptly in the early universe and we assume that a stable remnant is left behind. The PBHs remnants can constitute the entire dark matter of the universe for a wide range of remnant masses. We build inflationary models, in the framework of $\alpha$-attractors utilizing exponential functions, in which the PBHs are produced during matter, radiation and kination domination eras. The advantage of these inflationary models is that the spectral index takes values favorable by the Planck 2018 data. The PBH production from runaway inflaton models has the unique and very attractive feature to automatically reheat the universe. In these models the PBHs are produced during the kination stage and their prompt evaporation efficiently produces the required entropy. Such runaway models are remarkably economic having interesting implications for the early universe cosmology, possibly giving rise to a wCDM late time cosmology as well.