2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/58347We consider a general d-dimensional quantum system of non-interacting particles, with suitable statistics, in a very large (formally infinite) container. We prove that, in equilibrium, the fluctuations in the density of particles in a subdomain of the container are described by a large deviation function related to the pressure of the system. That is, untypical densities occur with a probability exponentially small in the volume of the subdomain, with the coefficient in the exponent given by the appropriate thermodynamic potential. Furthermore, small fluctuations satisfy the central limit theorem.28 pages, LaTeX 2eMathematical PhysicsStatistical Mechanics82B10; 82B21; 60F10text