Composite objects in quantum (super)gravity

TL;DR

This paper explores the concept of geons as dark matter candidates using quantum gravity models, combining analytic and numerical methods, and extends the analysis to supergravity to address supersymmetry observability.

Contribution

It introduces a novel numerical investigation of geons in quantum gravity via causal dynamical triangulations and extends the framework to supergravity scenarios.

Findings

Dependence of geon properties on cosmological time

Unexpected features in numerical simulations

Insights into supersymmetry's low-energy observability

Abstract

It has been a long entertained idea that self-bound gravitons, so-called geons, could be a dark matter candidate or form (primordial) black holes. The development of viable candidates for quantum gravity allows now to investigate these ideas. Analytic methods show that the description of geons needs to be based on composite operators made out of the graviton field. We present results from a numerical investigation into this idea using causal dynamical triangulations, an ab-initio non-perturbative definition of quantum gravity based on general relativity, and accessible in lattice-gauge-theory-like simulations. Our results suggest an interesting dependence on cosmological time and other unexpected features. Finally, we extend the analytic part of the setting to a supergravity scenario. This provides hints which, if confirmed, could explain why supersymmetry may in a realistic universe in principle not be observable at low (collider) energy scales.