Here is an argument that physicists should consider given 45 years of negative results regarding WIMPs, axions, sterile neutrinos, whateverons.
Right on cue a second gravitational wave event has been reported.
http://www.nature.com/news/ligo-detects-whispers-of-another-black-hole-merger-1.20093 Blurb from Nature piece: “this second event suggests that there is a large population of black hole pairs out there …”.
Other astrophysicists* (see below) have proposed that primordial black holes are the dark matter, which is also what Discrete Scale Relativity/Fractal Cosmology has predicted since 1985.
http://www.academia.edu/2917630/Predictions_of_Discrete_Scale_Relativity Primordial black holes in the stellar-mass and planetary-mass ranges might also help to explain the very large numbers of mysterious fast radio burst sources, the sources of gamma-ray bursts, the very large inferred population of "rogue" planetary-mass objects discovered via microlensing, and the very large numbers of stellar-mass MACHO objects discovered in additional microlensing observations.
Robert L. Oldershaw
http://www3.amherst.edu/~rloldershaw Fractal Cosmology/Discrete Scale Relativity
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* Kashlinsky has a recent paper published in the Astrophysical Journal (24 May 2016) that discusses a possible relationship among the topics listed in the subject line of this post.
http://arxiv.org/abs/1605.04023 .
Dark Matter in the form of primordial black holes may have generated the gravitational waves recently detected by LIGO. If such PBHs constitute a significant fraction of the Dark Matter, then this might explain the unexpected irregularity of the Cosmic Infrared Background, and also the unexpected finding that the CIB and the Cosmic X-ray Background have approximately correlated irregularities.
Kashlinsky noted that the idea could be tested via its prediction that LIGO should discover additional gravitational wave events corresponding to mergers of BHs with masses on the order of 30 solar mass. He did not have to wait long for that second event.
* Additionally, M.R.S. Hawkins has offered a cogent and empirically-supported case for stellar-mass and planetary-mass ultracompacts (with primordial black holes being the most likely candidates) as the mystery objects causing microlensing events seen in galactic bulge, galactic halo and quasar research. [papers available for free:
http://arxiv.org/abs/1106.3875 and
http://arxiv.org/abs/1503.01935 ].
A huge population of primordial black holes satisfies the non-baryonic constraint, might also explain where cosmic rays primarily come from, and might explain why the ARCADE-2 experiment found a unexplained factor-of-6 excess in cosmological radio emission.
Why do physicists insist that the dark matter must be in the form of chronically AWOL hypothetical subatomic particles? Why is there so little interest in, and media coverage of, astrophysical dark matter? Did a fractal theory in 1985 solve the dark matter enigma that has eluded conventional physics for about 40 years?