However QST should reveal itself, as discussed here below, causing an electromagnetic interaction of $neutral$ fields. This was noticed at the beginning as well but looked even less promising of visible consequences (see however [@CJSWW]).

But the recent years brought increasing evidence of the role of dark matter, and the possibility of collapse of huge dark matter binary systems; near the collapse, could those systems emit a seizable amount of electromagnetic radiation, and thus show a signature of the quantum nature of spacetime at the Planck scale?

In this note we discuss this problem, and show that a primitive, semiclassical evaluation of that emission gives again a very small result: the fraction of the mass of such a system converted into electromagnetic radiation per unit time by the mechanism envisaged here would be less than $10^{-89} s^{-1}$; nothing comparable to the few percents of the total mass converted into the gravitational wave radiation in the recently observed merges of binary black holes, GW150914 and GW151226, which inspire the numerical input of our calculation.

Our discussion proceeds as follows. In Sec. 1, after having recalled the main terminology, notations and results about the model of QST that we use, we discuss 