In TGD Universe ideal blackhole a space-time region with Euclidian(!) signature of induced metric and horizon would correspond to the light-like 3-surface at which the signature of the metric changes. Ideal blackhole (or rather its surface) would consist solely of dark matter. The large values of gravitational Planck constant hgr= GMm/v0, M here is the mass of blackhole and m is the mass of say electron, would be associated with the flux tubes mediating gravitational interaction and gravitational radiation. v0 is a parameter with dimensions of velocity - some characteristic rotational velocity -say the rotation velocity of blackhole- would be in question.
The quanta of dark gravitational radiation would have much large energies E= heff than one would expect on basis of the rotation frequency, which corresponds to a macroscopic time scale. Dark gravitons would arrive as highly energetic particles along flux tubes and could decay to bunches of ordinary low energy gravitons in the detection. These bunches would be bursts rather than continuous background and would be probably interpreted as a noise. I have considered a model for this in here.
See the article TGD view about blackholes and Hawking radiation.
For a summary of earlier postings see Links to the latest progress in TGD.