MOND v LambdaCDM

I have a soft spot for MOND. Yes, it's a silly sounding name but I kind of like it. I must admit that this is because $\Lambda$CDM feels a bit contrived. The $\Lambda$CDM models requires dwarf galaxies to be missing approximately 99% of the baryons associated to their dark matter halo. A bit unnecessary perhaps? Maybe there is a simpler answer?

For the record, however, $\Lambda$CDM is an established model that has convinced many people are who more technically orientated to cosmology than myself and therefore due respect is needed.

In any case McGaugh's new paper, "A novel test of the modified newtonian dynamics with gas rich galaxies" hits my soft spot. It's a nicely written, 4 page, paper that demonstrates that as a phenomenological model MOND should at the least be assumed to be giving some accurate picture of gravity at very large scales. The reduced $\chi^2$ for the prediction of MOND for the data used in the paper, depending on some technical assumptions about what counts as a degree of freedom, is between 0.96 and 0.99. So the data fits nicely. Figure 2 of the paper demonstrates that $\Lambda$CDM is substantially worse (the $\Lambda$CDM prediction doesn't lie in the error bars of any of the data points).

More kudos to McGaugh, as the paper contains a nicely balanced discussion of this which doesn't jump to sudo-crackpot accusations and gives $\Lambda$CDM the respect it deserves. And it's readable by lay-physicists!

So you know... I kind of like the paper.