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abstract: 'A $\cU(1)$ gauge theory turns, on physically motivated models of Quantum Spacetime, into a $\cU(\infty)$ gauge theory, hence free classical electrodynamics is no longer free and neutral fields may have electromagnetic interactions. We discuss the last point for scalar fields, possibly describing dark matter; we have in mind the gravitational collapse of binary systems or future applications to self gravitating Bose-Einstein condensates as possible sources of evidence of quantum gravitational phenomena. The effects so far considered, however, seem too faint to be detectable at present.'
author:
- Sergio Doplicher
- Klaus Fredenhagen
- Gerardo Morsella
- Nicola Pinamonti
title: Pale Glares of Dark Matter in Quantum Spacetime
---

Introduction
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One of the main difficulties of present day Physics is the lack of observation of quantum aspects of gravity; Quantum Gravity has to be searched without guide from nature, except the need to explain the observed universe as carrying traces of quantum gravitational phenomena in the only “laboratory” suitable to those effects, the universe itself few instants after the Big Bang.

Looking forward to see those traces in the cosmic gravitational waves background (for the analysis of quantum linearized perturbations see the pioneering work [@MFB], see also [@BFHPR]), 