A challenge for Cold Dark Matter

In a recent paper (see the arXiv version here) Stacy Mc Gaugh has obtained an observational result (tight correlation between the rotation velocity and baryonic mass, a.k.a. Baryonic Tully-Fisher Relation) that challenges the standard LambdaCDM model, and appears to favor instead the so-called MOdified Newtonian Dynamics (MOND) theory.

MOND is known to provide an excellent explanation of astrophysical observations of Galactic scales, and in the framework of this theory it is possible to get rid of the Dark Matter hypothesis through a suitable modification of the law of Gravity. However, it is also known that MOND does NOT provide a satisfactory explanation of clusters, and needs dark matter (‘massive’ neutrinos are often invoked) to explain lensing observation on these scales.

Independently form Mond, this result represents a new challenge for the Cold Dark Matter model (that, let’s not forget, otherwise performs well on many astrophysical ad cosmological observations).