that later on this process looses efficiency after the halo turn-around. This is due to the reduction of halo inertia by collapse, and to the continued expansion of the neighboring matter responsible for the tidal torque.

There are several analytic studies of the TTT scenario [@White1; @Doro1; @Peebles1; @Catelan3], as well as semi-analytic approaches [@Catelan1], and fully non-linear work using cosmological simulations [@Barnes1; @Suger1; @Porciani1; @Porciani2; @Peirani1; @Nagashima1]. The agreement is that the resulting halo population is poorly rotationally supported; the velocity dispersion at virialisation is found to be the most important mechanism for halo equilibrium. As a result, the distribution of spin parameters[^1] is log-normal which peaks at quite low values, $\lambda_{med} \simeq 0.035$ [@Bullock1; @Gardner1; @Onghia1; @Maccio1; @Bett1]. Unfortunately it is not possible to obtain a direct measurement of spin parameters in actual galaxies. Despite this, @Hernandez1 used indirect methods to derive distributions of galaxy spin parameters consistent with theoretical predictions.

From an observational point of view, it can be easier in some cases to determine the direction of the angular momentum of a given galaxy rather than its amplitude. There has been a recent increase in the interest concerning the possibility of galaxy alignments with the large 