  We report our results on the adsorption of noble gases such as argon, krypton
and xenon on a graphene sheet, using Grand Canonical Monte Carlo (GCMC)
simulations. We calculated the two-dimensional gas-liquid critical temperature
for each adsorbate, resulting in fair agreement with theoretical predictions
and experimental values of gases on graphite. We determined the different
phases of the monolayers and constructed the phase diagrams. We found
two-dimensional incommensurate solid phases for krypton, argon and xenon, and a
two-dimensional commensurate solid phase for krypton.
