On the Influence of Angular Momentum and Dynamical Friction on Structure Formation

In this paper we extended the spherical collapse model to take account of angular momentum and dynamical friction and studied how the accreted mass, the threshold of collapse, the virial overdensity, and the mass function change. Solving the equation of motion we got the relationships between mass, M, and the turn-around radius R-0. This relation is important because knowing one can obtain the mass accreted by the structure. We see that moving from the simple spherical collapse to that accounting for angular momentum and dynamical friction leads to the increase of acquired mass. Then, we showed how angular momentum, and dynamical friction change the threshold of collapse with mass, and also with redshift for different dark energy models. We repeated the calculation for the virial overdensity, and the mass function, founding noteworthy differences with the case of the simple spherical collapse.