# Primordial Black Hole Remnants as Dark Energy and an Instability of De Sitter Space towards Power-Law Accelerating Expansion

## TL;DR

The paper proposes primordial black hole remnants as a candidate for dark energy, explores de Sitter space instability towards power-law expansion, and discusses implications for gravitational wave background.

## Contribution

It introduces the PBHR model linking black hole remnants to dark energy and analyzes de Sitter space instability and gravitational wave signals.

## Key findings

- PBHRs can account for dark energy within observational limits.
- De Sitter space exhibits a dominant instability towards power-law expansion.
- Predicted gravitational wave background from PBHs is consistent with current constraints.

## Abstract

Starting from a discussion of the black hole information loss paradox, we argue that Primordial Black Hole Remnants (PBHRs) of Planck mass, should they exist, are a plausible candidate for dark energy. We call this proposal the PBHR model. We also find an instability of de Sitter space towards a space with power-law accelerating expansion, the time dependence of the cosmological constant and the resulting form of the metric, and propose that this is the dominant instability of de Sitter space. We conjecture that a similar instability does not afflict a space sourced by PBHRs. We find that the PBHR model satisfies the upper limits on $\beta$, the fraction of the Universe's mass in PBHs at their formation time, for a fair range of initial PBH masses. We derive information on the present day gravitational wave background due to the PBHs in our scenario.