Wednesday, January 26, 2022

Superfluid Dark Matter Has Some Issues

A recent pre-print, with two of my favorite physicist physics bloggers (McGaugh and Hossenfelder) collaborating as co-authors, examines the fit of Mistele and Hossenfelder's superfluid dark matter hypothesis to a large sample of galactic rotation curves, compares its performance to Modified Newtonian Dynamics (MOND) and finds it wanting.
We make rotation curve fits to test the superfluid dark matter model. Our aim is to investigate whether superfluid dark matter provides satisfactory fits to galactic rotation curves with reasonable stellar mass-to-light ratios. We fitted the superfluid dark matter model to the rotation curves of 169 galaxies in the SPARC sample. We found that the mass-to-light ratios obtained with superfluid dark matter are generally acceptable in terms of stellar populations. However, the best fit mass-to-light ratios have an unnatural dependence on the size of the galaxy in that giant galaxies have systematically lower mass-to-light ratios than dwarf galaxies. A second finding is that the superfluid often fits the rotation curves best when the superfluid's force does not closely resemble that of Modified Newtonian Dynamics (MOND). In that case, we can no longer expect superfluid dark matter to reproduce the phenomenologically observed scaling-relations that make MOND appealing. If, on the other hand, we consider only solutions whose force approximates MOND well, then the total mass of the superfluid is in tension with gravitational lensing data. We conclude that even the best fits with superfluid dark matter are still unsatisfactory.
Tobias Mistele, Stacy McGaugh, Sabine Hossenfelder "Galactic Mass-to-Light Ratios With Superfluid Dark Matter" arXiv:2201.07282 (January 18, 2022).


neo said...

Mcgaugh suggested a paper Mond + sterile neutrinos to explain evidence

Is an 11 eV sterile neutrino consistent with clusters, the cosmic microwave background and modified Newtonian dynamics?
G. W. Angus

In this paper, we show that if a single sterile neutrino exists such that forumla⁠, it can serendipitously solve all outstanding issues of the Modified Newtonian Dynamics. We focus on fitting the angular power spectrum of the cosmic microwave background (CMB) in detail which is possible using a flat Universe with forumla and the usual baryonic and dark energy components. One cannot match the CMB if there is more than one massive sterile neutrino, nor with three active neutrinos of 2 eV. This model has the same expansion history as the Λ cold dark matter (ΛCDM) model and only differs at the galactic scale, where the modified dynamics outperform ΛCDM comprehensively. We discuss how an 11 eV sterile neutrino can explain the dark matter of galaxy clusters without influencing individual galaxies and potentially match the matter power spectrum.

andrew said...

I'll take a look if I have time.