Dark Matter – cuspy core problem.
Proposed solution is that dark matter wakes up, turns into matter and then self repels/forms stars, etc.This means no cusp is found.
Note how in the most tenuous gas clouds (well cold ones – the hot tenuous galactic halo does not count as its a supernova effect), the density is the exact same as the dark matter density?
From https://arxiv.org/pdf/1404.1938.pdf – note how dark matter is about about 0.2 protons per cm^3 (BR 13 measurement) . One would think that in the disk of the milky way, this close to the galactic core that the DM density is about as large as it gets. Which seems right:
The Dark Matter Halo of the Milky Way, AD 2013 – https://arxiv.org/pdf/1304.5127v2.pdf
We find that the cored profile is the preferred one, with a shallow central density of ρH ∼ 4 × 107M⊙/kpc3 and a large core radius RH ∼ 10kpc, as observed in external spirals and in agreement with the mass model underlying the Universal Rotation Curve of spirals.
From wikipedia https://en.wikipedia.org/wiki/Interstellar_medium
Note how the lowest density clouds are 0.2 – 0.5 protons/cm^3
Why is this the same density? Answer: The dark matter has a maximum density, if density gets higher it lights up and turns into protons/electrons/H – which results in WIM and WNM clouds. Dark matter might be sleeping matter.
There is a problem – what heats the Warm Ionized Medium?
Journal, T. A. (2000). EVIDENCE FOR AN ADDITIONAL HEAT SOURCE IN THE WARM IONIZED MEDIUM OF GALAXIES, (Rand 1998), 1997–2000.
Dark Matter waking up might naturally result in WIM over WNM.
You can see a clear (well kinda clear -its astronomy data…) cut at 0.04 electrons (ie protons too) per cm3. http://www.astro.wisc.edu/wham/papers-dir/hill_sins.pdf
To me this is exciting. WIM has a density wall at about 0.02 particles / cm3 – while dark matter has a density of about the same number (within a factor of 10).
The maximum density of dark matter is about equal to the low-density wall of WIM.
Dark matter does not exist at high densities. So on a galaxy rotation curve, ie
ie – right at about the 15 kPc mark. Dark matter really not needed much below 10 kPc at all. Dark matter turns into regular matter at about these distances. Clumps of regular matter (which is how they get the rotation curves) are centers for DM – regular matter promotion. This promotion results in anomalous heating of the WIM.
Also see: – the ionizing problem is still around. The O star theory seems kinda weak…
Thus O stars are able to ionize the WIM (other obvious sources of Ionizing radiation are weaker), but how do the ionizing photons get from the location of these stars in the thin disk of the Milky Way to far above the mid-plane?
Their new calculations take into account that in general the dark matter will be a mixture of superfluid and normal fluid, and both phases will make a contribution to the gravitational pull. Just what the composition is depends on the gravitational potential (caused by all types of matter) and the equation of state of the superfluid. In the new paper, the authors parameterize the general effects and then constrain the parameters so that they fit observations.
1) Why isn't the condensate irreversibly scavenged by the central black hole, and others, over redshift? Black holes should be visibly snacking between meals. ... 2) Added thermodynamic degrees of freedom are spectroscopically invisible? ... 3) The condensate remains unperturbed by compact-body mergers, not perturbing LIGO waveforms?
Yet the theory does solve the cuspy core problem, etc – and you can see why…
The main reason I find this idea convincing is that it explains why some observations are easier to account for with dark matter and others with modified gravity: It’s because dark matter has phase transitions! It behaves differently at different temperatures and densities. In solar systems, for example, the density of (normal) matter is strongly peaked and the gradient of the gravitational field near a sun is much larger than in a galaxy on the average. In this case, the coherence in the dark matter fluid is destroyed, which is why we do not observe effects of modified gravity in our solar system. And in the early universe, the temperature is too high and dark matter just behaves like a normal fluid.