Effects of primordial black holes quantum gravity decay on galaxy clustering

TL;DR

This paper explores how quantum gravity-induced decay of primordial black holes could influence galaxy clustering, proposing that future measurements can test quantum gravity models and constrain primordial black hole populations.

Contribution

It introduces a method to use galaxy clustering data to test quantum decay models of black holes and constrain primordial black hole abundance.

Findings

Future galaxy clustering measurements can set constraints on quantum gravity parameters.

Non-detection could rule out small primordial black holes or the quantum decay scenario.

Observations could reveal quantum effects on black hole final states.

Abstract

It has been recently suggested that small mass black holes (BHs) may become unstable due to quantum-gravitational effects and eventually decay, producing radiation, on a timescale shorter than the Hawking evaporation time. We argue that the existence of a population of low-mass Primordial Black Holes (PBHs) acting as a fraction of the Universe dark matter component can be used to test proposed models of quantum decay of BHs via their effect on galaxy number counts. We study what constraints future galaxy clustering measurements can set on quantum-gravity parameters governing the BH lifetime and PBH abundance. In case of no detection of such effects, this would rule out either the existence of a non-negligible number of small PBHs, or the BH quantum decay scenario (or both). In case of independent observations of PBHs, the observables discussed here could be used to study the quantum effects that modify the final fate of BHs.