Can Gravitational Wave Data Shed Light on Dark Matter Particles ?

TL;DR

The work investigates whether gravitational wave observations that validate the Hawking Area Theorem can constrain the logarithmic corrections to black hole entropy from quantum gravity effects. By combining non-perturbative Loop Quantum Gravity results (which yield a fixed negative coefficient $s_0^{lqg}=-\tfrac{3}{2}$) with perturbative entanglement-entropy corrections (where $s_0^{ent,1}$ depends on the spin and number of species of fluctuating fields), the paper computes the total logarithmic coefficient $s_0=s_0^{lqg}+s_0^{ent,1}$ and imposes the absolute-consistency requirement $s_0<0$. Numerical examples show SM-only spectra satisfy the constraint, while adding certain BSM species (e.g., axions and gravitons) can flip the sign, thereby constraining the viable dark matter candidates and the spectrum of new particles. The results tie GW phenomenology to quantum gravity models, offering a potential observational handle on the Beyond-Standard-Model sector and dark matter hypotheses through black hole thermodynamics.

Abstract

Gravitational wave (GW) data from observed binary black hole coalescences (BBHC) have been demonstrated in recent analyses to validate the Hawking Area Theorem (HAT) for black hole horizons. The result of such analyses is imposed here as a criterion of {\it absolute} consistency on the logarithmic (in horizon area) corrections to the Bekenstein-Hawking Area Formula (BHAF) for the black hole entropy, when these corrections are computed both from non-perturbative quantum fluctuations of spacetime in matter-free quantum general relativity, as well as arising due to perturbative quantum matter field fluctuations around a stationary classical black hole background spacetime. This criterion of absolute consistency is seen to be obeyed provided certain restrictions ensue on the spin-parity and number of species of the spectrum of quantum matter fluctuations. Such constraints appear to restrict the Beyond-Standard-Model (BSM) part of the matter fluctuation spectrum. Some species of the constrained, yet-unobserved BSM particle spectrum are currently under active consideration in particle cosmology as candidates for dark matter.