The main goal of this project is to broaden the present understanding of the relaxation process (violent relaxation) in dark matter halos and collisionless self-gravitating systems in general, as well as to characterize, with simple theoretical models, the stationary state achieved at the end of this process. This study will use numerical siulation data, generated with the code GADGET-2, in order to test models for the velocity distribution in dark matter halos. Specifically, we will test the velocity distribution associated to the model recently proposed by us (and accepted for publication in Physical Review D), which associates the mixing level of the system with the indistinguishability of its constituents. This model also raises some doubts about the validity of the Vlasov equation during the violent relaxation, and thus we will test the validity of this equation with the simulation data. We will also test the correction to the velocity distribution due to the Landau Damping phenomenon, which is expected to occur during violent relaxation. From the observational point of view, we will use the projected density profiles of galaxy clusters, obtained via gravitational lensing, in order to test different theoretical models for the density profile. Particulalry, we will test the model called DARKexp (which was already tested with another data set), a model recently proposed (but not compared yet with observational data) which relates conserved actions and the maximum entropy principle, and finally we will test the density profile associated to the model proposed by us and cited previously.
News published in Agência FAPESP Newsletter about the scholarship: