Efecto Casimir en modelos O(N) críticos mediante simulaciones de Monte Carlo fuera de equilibrio

O(N) vector models in three dimensions, when defined in a geometry with a compact direction and tuned to criticality, exhibit long-range fluctuations which induce a Casimir effect. The strength of the resulting interaction is encoded in the excess free-energy density, which depends on a universal coefficient: the Casimir amplitude. We present a high-precision numerical calculation of the latter by means of a nonequilibrium Monte Carlo algorithm and compare our findings with results obtained from large-N expansions and from the conformal bootstrap.