The Tully-Fisher relation (aka Baryonic TFR) is remarkable. As the diagram below shows, the relationship between Vf and the baryonic mass of galaxies is just too finely tuned to be caused by dark matter. Something is up. Vf is the stellar orbit velocity in the galactic halo. For more details see the paper by Lelli, McGaugh and Schombert .
MOND (MOdified Newtonian Dynamics) is one explanation for the Tully-Fisher relation. It posits that the force towards the centre of a galaxy at large distances is not simply that of Newton, but is modified with the a0 of 1.2×10-10m/s2 in all galaxies in addition to the usual force predicted by standard Newton or General Relativity’s gravity. LCDM Dark matter is a clumsy explanation for the BTFR, as it needs fine tuning for every galaxy (or every galaxy type) in order to make that straight line be so, well, straight.
There is another way to generate an inward acceleration.
We need a force on each nucleon that changes with how much matter is inside the radius where the particle is. It somehow ‘knows’ the gravitational potential at R, and has a force that depends on that!
What I have so far on this is something to do with dark energy being more concentrated in galaxy cores, so the particle feels this dark energy slope and responds to it.
NOTE: This needs to include a dependence on the enclosed M (ie enclosed Dark Energy inside R). I call this emission based acceleration ‘Anomalous radial nucleonic radiation’ (ARNR). MOND tells us that particles in the galactic halo can ‘weigh’ the galaxy. They have that information. So there must/might be something like dark energy concentrated in the galaxy and the particles react to this, pushing radiation outward and reacting inward. Note in the galactic core the divergence of the DE is 0 – so no extra force on the particle in the middle of the galaxy.
It might seem strange to have this concerted outward radiation pattern though! Here are some possible explanations for an outward constant radiation by the halo constituents.
- I’m a fan of super high (nuclear and above) frequency gravitational wave (HFGW) emission/absorption in atoms and nuclei. So we might have some sort of stimulated emission from nucleons based on the outward flow of HFGW out of a galaxy.
- Dark Energy has a value of about 1GeV/m3 . If this energy is concentrated by the galactic core, then maybe some the nucleon has a force toward the centre of the galaxy in response to the divergence of the DE field. (i.e. lower radiation resistance in the outward direction). This Dark Energy may be some new field, (or HFGW).
- Some other mechanism. We don’t have to know the mechanism to predict some consequences.
People don’t generally like the MOND theories because general relativity (GR) in its usual form is so well tested and accurate. LCDM is disliked by many because of the fine-tuning required in order to get everything to match observations. ‘Anomalous radial nucleonic radiation’ (ARNR) allows GR to exist as is.
Consequences of ARNR
If nuclei really do radiate continuously, (perhaps in violation of quantum – mechanics) then there will be experimental consequences. These consequences may be largely hidden from earth-based experiments, as the emission would be isotropic and take place in some field (such as gravitational waves) that is hard to detect with current instruments.
There may be other places where cosmological or galactic cluster observations might note this energy output.
In other posts, I have wondered if dark matter is ‘sleeping regular matter‘ and I still think that it may be a viable option, but it seems like any explanation in terms of dark matter may need to be fine-tuned to match observations.