Conventional lattice formulations of θ vacua in the 1+ 1-dimensional O (3) nonlinear sigma
model suffer from a sign problem. Here, we construct the first sign-problem-free …

Ab initio studies of strongly interacting bosonic and fermionic systems are greatly facilitated
by efficient Monte Carlo algorithms. This article emphasizes this requirement and outlines …

I will review recent progress on addressing large N gauge theories on the lattice. The focus
will be put on the use of large N volume independence as an effective tool to compute non …

The Berezinskii-Kosterlitz-Thouless (BKT) essential phase transition in the 2d XY model is
revisited. Its mechanism is usually described by the (un) binding of vortex--anti-vortex (V …

En este trabajo se presentan resultados numéricos del modelo XY bidimensional con el fin
de analizar la transición de fase de Berezinskiı-Kosterlitz-Thouless (BKT). Existe especial …

In this thesis, the Wolff multi-cluster algorithm was used to simulate the two dimensional XY
model. First improved estimators for the magnetic susceptibility and the spin-spin correlation …