Non-extensive processes associated with heating of the Galactic disc
  We analyse the mechanisms ruling galactic disc heating through the dynamics
of space velocities $U$, $V$ and $W$, extracted from the Geneva-Copenhagen
catalogue. To do this, we use a model based on non-extensive statistical
mechanics, where we derive the probability distribution functions that quantify
the non-Gaussian effects. Furthermore, we find that the deviation $q-1$ at a
given stellar age follows non-random behaviour. As a result, the $q$-index
behaviour indicates that the vertical component $W$, perpendicular to the
Galactic plane, does not ``heat up'' at random, which is in disagreement with
previous works that attributed the evolution of $W$ to randomness. Finally, our
results bring a new perspective to this matter and open the way for studying
Galactic kinematic components through the eyes of more robust statistical
models that consider non-Gaussian effects.
