One of the central goals of cosmology is to understand how the nearly uniform matter distribution of the early Universe evolved into the complex network of galaxies, clusters, and filaments observed today. My research addresses this problem from the perspective of statistical physics and gravitational dynamics.
A major focus has been the study of infinite self-gravitating systems, where gravity acts as a long-range force and drives the emergence of structure through collective interactions. To identify the fundamental mechanisms of gravitational clustering, we have developed simplified theoretical models that retain the essential physics while avoiding unnecessary complexities. These studies have shown that the key properties of cosmological structure formation can be understood within a general framework of non-equilibrium statistical mechanics.
An important aspect of this work concerns the relationship between cosmological N-body simulations and the underlying mean-field description of matter evolution. We have developed analytical and numerical methods to investigate the conditions under which finite-particle simulations accurately reproduce the collisionless (Vlasov) limit that underlies modern cosmological models. This has led to a series of tests aimed at assessing the accuracy, resolution, and physical reliability of large-scale cosmological simulations.
Another line of research has focused on the formation and properties of dark matter halos, the fundamental building blocks of cosmic structures. Understanding how halos form and evolve is essential for connecting theoretical predictions with observations of galaxies and large-scale structure.
More broadly, gravitational clustering provides a paradigmatic example of a system with long-range interactions. Unlike ordinary systems that relax toward thermodynamic equilibrium through short-range collisions, self-gravitating systems evolve through collective mean-field dynamics and can become trapped in long-lived quasi-stationary states. These phenomena are relevant not only for cosmology but also for a wide range of astrophysical systems, including star clusters and galaxies.
This research lies at the intersection of cosmology, gravitational dynamics, and statistical physics, with the broader goal of understanding how complex structures emerge from simple initial conditions under the action of gravity.
Francesco sylos labini 