Strongly-correlated many-body systems are extremely interesting. Due to the presence of correlations, the <\/span>behavior of individual particles cannot be considered as independent, giving rise to interesting and often <\/span>useful system properties. My group studies quantum phases of strongly-correlated lattice bosons. Lattice bosons can be experimentally engineered with ultracold atoms and molecules trapped in optical lattices, i.e. periodic arrays of potential wells.<\/span> Owing to considerable experimental advances, optical lattice systems have turned out to be an ideal, highly controllable experimental platform to study models and phenomena relevant to condensed matter systems, e.g. quantum magnetism, high temperature superconductivity. We study lattice bosons by means of large-scale quantum Monte Carlo techniques which, in the absence of sign-problem,<\/span> are approximation-free and produce unbiased results.<\/span> <\/p>\n