A unified solution to the small scale problems of the $\Lambda$CDM model
  We study, by means of the model proposed in Del Popolo (2009), the effect of
baryon physics on the small scale problems of the CDM model. We show that,
using this model, the cusp/core problem, the missing satellite problem (MSP),
the Too Big to Fail (TBTF) problem, and the angular momentum catastrophe can be
reconciled with observations. Concerning the cusp/core problem, the interaction
among dark matter (DM) and baryonic clumps of 1% the mass of the halo, through
dynamical friction (DF), is able to flatten the inner cusp of the density
profiles. We moreover assume that haloes form primarily through quiescent
accretion, in agreement with the spherical collapse model (SCM)-secondary
infall model (SIM) prescriptions. The results of this paper follow from the two
assumptions above. Concerning the MSP and TBTF problem, applying to the Via
Lactea II (VL2) subhaloes a series of corrections similar to those of Brooks et
al. (2013), namely applying a Zolotov et al. (2012)-like correction obtained
with our model, and further correcting for the UV heating and tidal stripping,
we obtain that the number of massive, luminous satellites is in agreement with
the number observed in the MW. The model also produces an angular momentum
distribution in agreement with observations, that is with the distribution of
the angular spin parameter and angular momentum of the dwarfs studied by van
den Bosch, Burkert, & Swaters (2001). In conclusion, the small scale problems
of the CDM model can all be solved by introducing baryon physics.
