Missing dark matter

One problem of ΛCDM scenario is missing of matter and dark matter in some places (see this). There missing dark matter in the scale of R=.2 Gy and also in the vicinity of solar system in the scale 1.5-4 kpc.

In the work titled “Missing Dark Matter in the Local Universe”, Igor D. Karachentsev studied a sample of 11,000 galaxies in the local Universe around the MW (see this). He summed up the masses of individual galaxies and galaxy-groups and used this to test a very fundamental prediction of ΛCDM.

1. Standard cosmology predicts the average fraction of matter to be Ω_m,glob=28+/- 3 per cent (83 percent of this would be dark and 17 per cent visible matter). 72 per cent would be dark energy, 28 per cent dark matter, and 4.8 per cent visible matter. To test one can simply sum up all the visible mass in certain large enough volume of space, deduce the density of dark matter from kinematical data, and calculate the total mass. Karachentsev chose the volume to be a sphere of L= .2 Gy since in this scale the density is expected to fluctuate only 10 per cent. Note that horizon radius is estimated to be about R_H=14 Gly giving R_H= 70 L.

2. The estimate for the total mass (dark matter plus visible matter assuming halo model) in a volume of radius .2 Gy gives Ω_m,glob=8+/- 3 per cent, which is only 28 per cent of the predicted fraction. The predicted fraction of visible matter is 4.8 per cent and marginally consistent with 8+/- 3 per cent but it seems plausible that also dark matter is present although its amount is much smaller than expected.
3. One explanation is that all matter has not been included. Second explanation is that the measurement region corresponds to a region with abnormally low density. The third explanation is that there is TGD based one.

In TGD based model most of the dark matter would reside at the long flux tube with which galaxy forms a bound state. Fractality suggests the presence of both larger and smaller flux tube structures (even stars could be pearls along necklace). Their presence could give a small contribution to the dark matter, which would be at most of the same size as that of visible matter.

The amount of dark matter in the solar neighborhood was investigated in the work “Kinematical and chemical vertical structure of the Galactic thick disk II. A lack of dark matter in the solar neighborhood” by Christian Moni Bidin and collaborators (see this). Moni Bidin et al have studied as sample of 400 red giants in the vicinity of solar system at vertical distances 1.5 to 4 kpc and deduce 3-D kinematics for these start. From this data they estimate the surface mass density of the Milky Way within this range of heights from the disk. This surface density should be sum of both visual and dark mass.

According to their analysis, the visible mass is enough to explain the data. No additional mass is needed. Only highly flattened dark matter halo would be consistent with the findings. This conforms with the TGD prediction that dark mass/energy are associated with magnetic flux tubes.

For a summary of earlier postings see Latest progress in TGD.

Articles and other material related to TGD.