Evaporating Kerr black holes as probes of new physics

TL;DR

This paper proposes that observing the mass and spin evolution of evaporating primordial black holes can serve as a gravitational probe for detecting new physics beyond the Standard Model, using multi-messenger astrophysical signals.

Contribution

It introduces a novel method to determine the presence and nature of new particles by analyzing PBH evaporation data, independent of their interactions with known particles.

Findings

Tracking PBH mass and spin reveals signatures of new particles.

Multi-messenger signals enable accurate measurement of PBH properties.

Method is robust against unknown interactions and distance uncertainties.

Abstract

In the string axiverse scenario, primordial black holes (PBHs) can sustain non-negligible spin parameters as they evaporate. We show that tracking both the mass and spin evolution of a PBH in its final hour can yield a purely gravitational probe of new physics beyond the TeV scale, allowing one to determine the number of new scalars, fermions, vector bosons, and spin-3/2 particles. Furthermore, we propose a multi-messenger approach to accurately measure the mass and spin of a PBH from its Hawking photon and neutrino primary emission spectra, which is independent of putative interactions between the new degrees of freedom and the Standard Model particles, as well as from the Earth-PBH distance.