Quenched and unquenched chiral perturbation theory in the ε-regime

The chiral limit of finite-volume QCD is the ε-regime of the theory. We discuss how this regime can be used for determining low-energy observables of QCD by means of comparisons between lattice simulations and quenched and unquenched chiral perturbation theory. The quenched theory suffers in the ε-regime from 'quenched finite volume logs', the finite-volume analogs of quenched chiral logs