title: Validity of projected Gross-Pitaevskii simulation: comparison with quantum Monte Carlo.
abstract: We examine the validity of the projected Gross-Pitaevskii simulation by taking the two-dimensional homogeneous bosonic system as an example. The long-distance behaviors of the correlation function and equilibrium temperatures show good agreement with those of the quantum Monte Carlo calculations below temperatures near the Kosterlitz-Thouless transition. We find that in the projected Gross-Pitaevskii description, one needs to estimate the optimal wave-number cutoff in temperature. In the well-described region, the projected Gross-Pitaevskii equation presents reliable predictions for the long-wave bosonic components.
authors.affiliation: Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Sato
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kato
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Naoki
authors.initials: N
authors.lastname: Kawashima