  The cold dark matter (CDM) scenario predicts that galactic halos should host
a huge amount of subhalos possibly lighter than planets, depending on the
nature of dark matter. Predicting their abundance and distribution has
important implications for dark matter searches and searches for subhalos
themselves, as they could provide a decisive test of the CDM paradigm. A major
difficulty in subhalo population model building is to account for the
gravitational stripping induced by baryons, which strongly impact on the
overall dynamics inside galaxies. In this paper, we focus on these "baryonic"
tides from analytical perspectives, summarizing previous work on galactic disk
shocking, and thoroughly revisiting the impact of individual encounters with
stars. For the latter, we go beyond the reference calculation of Gerhard and
Fall (1983) to deal with penetrative encounters, and provide new analytical
results. Based upon a full statistical analysis of subhalo energy change during
multiple stellar encounters possibly occurring during disk crossing, we show
that subhalos lighter than $\sim 1$~M$_\odot$ are very efficiently pruned by
stellar encounters. This modifies their mass function in a stellar environment.
In contrast, disk shocking is more efficient at pruning massive subhalos. In
short, if reasonably resilient, subhalos surviving disk crossing have lost all
their mass but an inner cuspy part, with a tidal mass function strongly
departing from the cosmological one. If fragile, stellar encounters make their
number density drop by an additional order of magnitude with respect to
disk-shocking effects only (e.g., at the solar position in the Milky Way). Our
results can be incorporated to any analytical or numerical subhalo population
model, as we show for illustration. This study complements those based on
cosmological simulations, which cannot resolve dark matter subhalos on such
small scales.
