In a recent preprint1 to be published in Astronomy and Astrophysics in 2006, a team of astrophysicists has carefully reanalyzed the data from microlensing observations towards the Large Magellanic Cloud galaxy. These observations were originally collected and analyzed by the MACHO collaboration in their search for dark matter signals (see paper #5 in the "Selected Papers" section of this website for a discussion of the initial results).
The newer analysis reveals that the inferred mass function for the dark matter has peaks at ≈ 0.15 M¤ and ≈ 0.5 M¤.
Table 1. Predicted and Observed Dark Matter Peaks
Atomic Scale Analogues
|
SSCP Predictions2
|
Observed DM Peaks1
|
p+ |
0.15 M¤ |
≈ 0.15 M¤ |
He++ |
0.58 M¤ |
≈ 0.5 M¤ |
e- |
8 x 10-5 M¤ |
? (see paper #5) |
In a paper published in the Astrophysical Journal in 1987, before any microlensing experiments had begun collecting data, the Self-Similar Cosmological Paradigm uniquely and definitively predicted2 that the microlensing teams would find dark matter mass peaks at 0.15 M¤, 0.58 M¤ and 8 x 10-5 M¤. Now it appears that the predicted peaks at 0.15 M¤and 0.58 M¤ have found their strongest support yet. There has also been some tantalizing evidence for a planetary-mass component of the dark matter (M ~ 10-4 M¤; see paper #5 of "Selected Papers") but the physical characteristics of this subpopulation remain poorly defined. The prediction of a large planetary-mass dark matter component could be verified or falsified by microlensing experiments with narrow time-resolutions (observations separated by ≤ 3 hours) that search for low-mass microlenses in nearby globular clusters.
Stellar-mass dark matter objects with mass peaks in the 0.1 M¤ to 0.6 M¤range appear to have been detected in experiments looking towards the LMC, SMC, MWG Bulge and M31. As pointed out by Calchi Novati et al1 regarding the LMC results, lensing by known stellar populations "cannot explain the signal, so that most of the detected events must belong either to the MW or to the LMC dark matter halo."
A huge number of attempts to observe WIMPS or other forms of particle-mass dark matter have come up empty-handed.
Given that the mass range of possible dark matter candidates stretches over 70 orders of magnitude, there is no way that one could guess the correct mass spectrum for the dark matter.
Given that the dark matter comprises ≥ 90% of the mass in the observable universe, a paradigm that cannot successfully predict the dark matter mass spectrum is not a very good paradigm.
Given the fundamental importance of the dark matter enigma, the paradigm that does successfully predict the dark matter mass spectrum will have proven that it is the unique path towards a new and more unified understanding of the cosmos.