Friday, December 29, 2017

Have galactic cosmic strings been observed?

I have been talking for a couple of decades or so about cosmic strings in TGD sense as explanation for the galactic dark matter. Long cosmic strings would have galaxies as knots in the simplest model of galaxies as pearls in necklace. The model explains the old observation that galaxies indeed form linear structures. Constant velocity spectrum for distant stars is predicted as being due to the gravitational field of cosmic string: string tension is the only parameter of the model. No dark matter halo, which is recently in deeper difficultiest than ever, is needed.

In pearls-in-necklace model (see this) galaxies are knots in long cosmic string. These knots in turn can decompose to further knots connected by more or less straight portions and one can image fractal structure continuing down to the level of stars. The straight portions would give rise to filament like structures connecting regions of sub-knots, which should correspond to regions. where star formation is taking place. Even the beams of particles from neutron stars could be associated with cosmic strings. Note that the string tension of cosmic string decreases as it thickens.

Quite recently I learned that there exists evidence for this kind of filaments (see this). The first filaments found were roughly orthogonal to the galactic plane but later filaments with random directions were found. This conforms with the knots along knots along... model.

Quite recently came a report by Morris, Zhao and Goss about a new filament found in Milky Way. As the title "A Nonthermal Radio Filament Connected to the Galactic Black Hole? " of the article tells that the filament visible at radio frequencies might emerge from galactic blackhole. There is also a popular article about the finding with title "A Mysterious Filament Is Stretching Towards Our Galaxy's Supermassive Black Hole".

The filament - known as Sgr A West Filament (SgrAW) - was actually discovered back in 2012. What is new that the new image suggests that the 2.3 light-year long filament is associated with the galactic blackhole Sagittarius A*. This suggests that galactic blackhole like object could be associated with a tight knot or self-intersection of cosmic string. Article consider the possibility that a low mass density cosmic string has been anchored to Sgr A*. Sgr A* would be a source of relativistic particles constrained to diffuse along ordered local field lines. Simplest model (vanishing of total momentum for particles coming out) suggests that the particle beam along filament is bi-directional. Filament is however seen only on one side of Sgr A*.

In TGD framework filament could be ordinary matter gravitationally bound with cosmic string and moving along it in essentially free motion. The beam could be due to ithe transformation of dark matter and/or energy of cosmic string to ordinary matter.

  1. The transformation of Kähler magnetic energy to particles would be TGD analog for the decay of the vacuum energy of inflaton field to particles. If Kähler magnetic energy dominates over volume term as it should, the thickening of cosmic string would weaken Kähler magnetic field and energy density and therefore string tension. The magnetic energy would be transformed to ordinary particles.

  2. A possible explanation for why the filament is seen only on one side of Sgr A* is that the decay of magnetic energy generates beams moving to opposite directions so that total momentum vanishes. The first beam remains inside cosmic string as dark particles and second beam leaks out as ordinary particles. Second possibility is that magnetic flux tube contains a beam of dark particles, which partially leaks out as ordinary particles.

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

Articles and other material related to TGD.

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