Analysis of a dark matter halo and its sub-halos in various dark matter models at different cosmological redshifts.

Baryonic matter alone is unable to correctly describe the data coming from astrophysical observations, and this has, over time, led to the hypothesis that there must therefore exist another type of matter, which, at least as far as is known to date, interacts only gravitationally: dark matter. Because of this, various hypotheses have been put forward over time about the nature of dark matter. It appears that on large scales, the best model is currently the standard cold dark matter model, which is consistent with observations. However, alternative scenarios, such as warm dark and self-interacting dark matter, have not been fully excluded, especially at smaller scales. These scenarios modify the internal structure of halos, thus predicting different forms of mass and velocity distributions as a function of radius, as well as central slopes. In this thesis, we are going to analyze numerical simulations that include different variations of dark matter. We focus on different characteristics, in particular mass distribution and the relationship between the maximum circular velocity and the radial distances at the achievement of dark matter halos and their ”substructures”, the subhalos. We will also analyze the interaction between dark matter and baryonic matter (galaxies, gas, and BH), which is why, for each dark matter model, we chose to study separately the cases in which only the latter is present and the cases in which baryonic matter is also considered. What is expected is therefore that for each case the behaviour and evolution should be different, and through the analysis itself, these differences are sought in the model(s) that best reproduce the observations.